“S S C e°s n s!o r r } COMMITTEE PBINT
WEATHER MODIFICATION:
PROGRAMS, PROBLEMS, POLICY, AND
POTENTIAL
Prepared at the Request of
Hon. Howard W. Cannon, Chairman
COMMITTEE ON COMMERCE,
SCIENCE, AND TRANSPORTATION-
UNITED STATES SENATE
Printed for the use of the
Committee on Commerce, Science, and Transportation
95 o5 o° n ? reSS \ COMMITTEE PRINT
2d Session J
WEATHER MODIFICATION:
PROGRAMS, PROBLEMS, POLICY, AND
POTENTIAL
Prepared at the Request of
Hon. Howard W. Cannon, Chairman
COMMITTEE ON COMMERCE,
SCIENCE, AND TRANSPORTATION
UNITED STATES SENATE
MAY 1978
Printed for the use of the
Committee on Commerce, Science, and Transportation
U.S. GOVERNMENT PRINTING OFFICE
WASHINGTON : 1978
34-857
COMMITTEE ON COMMERCE, SCIENCE, AND TRANSPORTATION
HOWARD W. CANNON, Nevada, Chairman
WARREN G. MAGNUSON, Washington
RUSSELL B. LONG, Louisiana
ERNEST F. HOLLINGS, South Carolina
DANIEL K. INOUYE, Hawaii
ADLAI E. STEVENSON, Illinois
WENDELL H. FORD, Kentucky
JOHN A. DURKIN, New Hampshire
EDWARD ZORINSKY, Nebraska
DONALD W. RIEGLE, Jr., Michigan
JAMES B. PEARSON, Kansas
ROBERT P. GRIFFIN, Michigan
TED STEVENS, Alaska
BARRY GOLDWATER, Arizona
BOB PACKWOOD, Oregon
HARRISON H. SCHMITT, New Mexico
JOHN C. DANFORTH, Missouri
Aubrey L. Sarvis, Staff Director and Chief Counsel
Edwin K. Hall, General Counsel
Malcolm M. B. Sterrett, Minority Staff Director
(H)
LETTER OF TRANSMITTAL
U.S. Senate,
Committee on Commerce, Science, and Transportation,
November 15 , 1978 .
To the members of the Committee on Commerce . Science, and
Transportation , £7.$. Senate:
I am pleased to transmit herewith for your information and use the
following report on “Weather Modification: Programs, Problems,
Policy, and Potential. 35
The report was prepared at my request by the Congressional Re-
search Service under the direction of Dr. Robert Morrison, Specialist
in Earth Sciences, Science Policy Research Division. We thank Dr.
Morrison and the others involved in the study for their extremely
thorough and scholarly report. Substantial material on almost all
areas of weather modification are included and the report will provide
the committee with an excellent reference source for future delibera-
tions on the subject.
The completion of the report is particularly timely due to the up-
coming recommendations expected from the Weather Modification
Advisory Board and the Department of Commerce (as directed by
Public Law 9-1-490) on the future Federal role in weather
modification.
James B. Pearson,
Ranking minority member .
(in)
LETTER REQUESTING STUDY
U.S. Senate,
Committee on Commerce, Science, and Transportation,
Washington, D.C .,July 30 , 1976 .
Dr. Norman A. Beckman,
Acting Director , Congressional Research Service ,
Library of Congress , IF ashington ,
Dear Dr. Beckman: Weather modification, although a relatively
young science, has over the years stimulated great interest within the
scientific, commercial, governmental, and agricultural communities.
Such responses are readily understandable. Weather-related disasters
and hazards affect virtually all Americans and annually cause untold
human suffering and loss of life and result in billions of dollars of eco-
nomic loss to crops and other property. While weather modification
projects have been operational for nearly 25 years and have been
shown to have significant potential for preventing, diverting, moderat-
ing, or ameliorating the adverse effects of such weather related disas-
ters and hazards, I am greatly concerned regarding the lack of a
coordinated Federal weather modification policy and a coordinated
and comprehensive program for weather modification research and
development. This fact is all the more disturbing in view of the mani-
fest needs, and benefits, social and economic, that can be associated with
weather modification activities. These deficiencies in our Federal orga-
nizational structure have resulted in a less than optimal return on our
investments in weather modification activities and a failure, with few
exceptions, to recognize that much additional research and develop-
ment needs to be carried out before weather modification becomes a
truly operational tool.
Reports and studies conducted by such diverse organizations as the
National Academy of Sciences, the National Advisor\ r Committee on
Oceans and Atmosphere, the General Accounting Office, and the
Domestic Council have highlighted the lack of a comprehensive Federal
weather modification policy and research and development program.
Hearings that I chaired in February of this year reinforced my con-
cerns regarding the wisdom of our continued failure to implement a
national policy on this very important issue.
I am therefore requesting the Congressional Research Service to
prepare a comprehensive report on weather modification. This report
should include a review of the history and existing status of weather
modification knowledge and technology; the legislative history of
existing and proposed domestic legislation concerning weather mod-
ification ; socio-economic and legal problems presented by weather
modification activities; a review and analysis of the existing local,
State, Federal, and international weather modification organizational
(V)
VI
structure; international implications of weather modification activi-
ties: and a review and discussion of alternative U.S. and international
weather modification policies and research and development programs.
If you have any questions with respect to this request, please contact
Mr. Gerry J. Ivovach, Minority Staff Counsel of the Senate Commerce
Committee. He has discussed this study with Mr. Robert E. Morrison
and Mr. John Justus of the Science Policy Division, Congressional
Research Service.
Very truly yours,
Jamies B. Pearson,
U.S. Senator .
LETTER OF SUBMITTAL
The Library of Congress,
Congressional Research Service,
TF ashington, D.C., June 19 , 1978 .
Hon. James B. Pearson,
Committee on Commerce , Science , Transportation ,
£7.#. Senate , Washington , £>.£7.
Dear Senator Pearson: Tlie enclosed report, entitled “Weather
Modification: Programs, Problems, Policy, and Potential,” has been
prepared by the Congressional Research Service in response to your
request.
The study reviews the history, technology, activities, and a number
of special aspects of the field of weather modification. Activities
discussed are those of the Federal, State, and local governments, of
private organizations, and of foreign nations. Consideration is given
to international, legal, economic, and ecological aspects. There are
also an introductory chapter which includes a summary of issues, a
chapter discussing inadvertent weather and climate modification, and
a chapter summarizing recommendations from major Federal policy
studies.
The study has been coordinated by Dr. Robert E. Morrison, Special-
ist in Earth Sciences, Science Policy Research Division, who also
prepared chapters 1, 2, 3, 5, 7, 8, and 9 as well as the Summary and
Conclusions. Mr. John R. Justus, Analyst in Earth Sciences, and
Dr. James E. Mielke, Analyst in Marine and Earth Sciences, both
of the Science Policy Research Division, contributed chapters 4 and
6, respectively. Chapter 10 was prepared by Mrs. Lois B. McHugh,
Foreign Affairs Analyst, Foreign Affairs and National Defense Di-
vision. Chapter 11 was written jointly by Mrs. Nancy Lee Jones,
Legislative Attorney, and Mr. Daniel Hill Zafren, Specialist in Ameri-
can Public Law, both of the American Law Division. Dr. Warren
Viessman, Jr., Senior Specialist in Engineering and Public Works,
contributed chapter 12; and Mr. William C. Jolly, Anatyst in En-
vironmental Policy, Environment and Natural Resources Division,
was responsible for chapter 13. In addition, appendixes C, F, Q, and R
were assembled by Mrs. McHugh ; appendixes D and S were prepared
by Mrs. Jones; and information in the remaining appendixes was
collected by Dr. Morrison.
I trust that this report will serve the needs of the Committee on
Commerce, Science, and Transportation as well as those of other
committees and individual Members of Congress who are concerned
with weather modification. On behalf of the Congressional Research
Service, I wish to express my appreciation for the opportunity to
undertake this timely and worthwhile assignment.
Sincerely,
Gilbert Gtjde,
Director .
(VII)
Digitized by the Internet Archive
in 2013
http://archive.org/details/weatificatOOunit
CONTENTS
Page
Letter of transmittal in
Letter requesting study v
Letter of submittal vn
Summary and conclusions xix
Chapter 1
Introduction and summary of issues 1
Perspective 1
Situation 1
Advantages 3
Timeliness 5
Definitions and scope of report 7
Summary of issues in planned weather modification 9
Technological problems and issues 9
Governmental issues 12
The role of the Federal Government 12
Roles of State and local governments 14
Legal issues 15
Private rights in the clouds 15
Liability for weather modification 1G
Interstate legal issues 17
International legal issues 17
Economic issues 18
Issues complicating economic analyses of weather modifica-
tion 18
Weather modification and conflicting interests 19
Social issues 19
Social factors 20
Need for public education on weather modification 21
Decisionmaking 22
International issues 23
Ecological issues 24
Chapter 2
History of weather modification 25
Introduction 25
History of weather modification prior to 1946 26
Prescientific period 26
Early scientific period 27
Development of scientific fundamentals 32
Early cloud-seeding experiments 34
Weather modification since 1946 35
Chronology 35
Langmuir, Schaefer, and Yonnegut 37
Research projects since 1947 39
Project Cirrus 39
The Weather Bureau cloud physics project 41
The U.S. experiments of 1953-54 42
Arizona Mountain cumulus experiments 44
Project Whitetop 44
Climax experiments 45
Lightning suppression experiments 46
Fog dispersal research 46
Hurricane modification. 46
Hail suppression 46
Foreign weather modification research 47
Commercial operations 48
History of Federal activities, committees, policy studies, and
reports 53
(IX)
X
Chapter 3
Page
Technology of planned weather modification 55
Introduction 55
Assessment of the status of weather modification technology 56
Classification of weather modification technologies 61
Principles and status of weather modification technologies 62
Precipitation augmentation 64
Cumulus clouds 66
Cumulus modification experiments 67
Effectiveness of precipitation enhancement research and
operations 69
Results achieved through cumulus modification 70
Recent advances in cumulus cloud modification 71
Orographic clouds and precipitation 71
Orographic precipitation modification 75
Orographic seeding experiments and seedability criteria 77
Operational orographic seeding projects 81
Results achieved through orographic precipitation modifi-
cation 82
Hail suppression 84
The hail problem 84
Modification of hail 86
Hail seeding technologies 87
Evaluation of hail suppression technology 88
Surveys of hail suppression effectiveness 89
Conclusions from the TASH study 91
Dissipation of fog and stratus clouds 92
Cold fog modification 93
Warm fog modification 93
Lightning suppression 96
Lightning modification 98
Evaluation of lightning suppression technology 99
Modification of severe storms 101
Hurricanes 101
Generation and characteristics of hurricanes 104
Modification of hurricanes 108
Tornadoes 112
Modification of tornadoes 113
Technical problem areas in planned weather modification 115
Seeding technology 115
Evaluation of weather modification projects 118
Extended area effects of weather modification 124
Approaches to weather modification other than seeding 129
Research needs for the development of planned weather modification. 131
General considerations 131
Recommendations from the 1973 National Academy of Sciences
study I 134
Recommendations of the Advanced Planning Group of NOAA___ 136
Summary of Federal research needs expressed by State officials. 138
Research recommendations of the AMS Committee on Weather
Modification 139
Research recommendations related to extended area and time
effects 143
Chapter 4
Inadvertent weather and climate modification 145
Introduction 145
Terminology 145
Climate 145
Climatic fluctuation and climatic change 146
Weather 146
Weather modification 146
Climate modification 146
Planned climate modification 147
Inadvertent climate modification 148
XI
Page
Background 149
Historical perspective 149
Understanding the causes of climatic change and variability 151
The concept of climatic change and variability 152
When and how do climatic changes occur 154
The facts about inadvertent weather and climate modification 156
Airborne particulate matter and atmospheric turbidity 156
Do more particles mean a warming or cooling? 157
Sources of atmospheric particulates: Natural vs. manmade.. 158
Atmospheric processes affected by particulates 159
The La Porte weather anomaly: Urban climate modification- 162
Carbon dioxide and water vapor 164
Increases in atmospheric carbon dioxide concentration:
What the record indicates 164
Predicting future atmospheric carbon dioxide levels 166
Sources and sinks for carbon dioxide 168
Atmospheric effects of increased carbon dioxide levels 169
Implications of increasing atmospheric carbon dioxide con-
centrations 169
Implications of a climatic warming 170
Carbon dioxide and future climate: The real climate vs.
1 1 model climate” 171
Ozone depletion 172
Concerns regarding ozone destruction 172
Action by the Government on the regulation of fluorocar-
bons 175
Climatic effects of ozone depletion 176
Waste heat 177
The urban “Heat Island” 177
Albedo 179
Large-scale irrigation 180
Recapitulation 181
Issues in inadvertent weather and climate modification 184
Climatic barriers to long-term energy growth 184
Thoughts and reflections — Can we contemplate a fossil-fuel-free
world? 185
Research needs and deficiencies 186
Chapter 5
Federal activities in weather modification 193
Overview of Federal activities — 193
Legislative and congressional activities 194
Federal legislation on weather modification 194
Summary 194
The Advisory Committee on Weather Control 195
Direction to the National Science Foundation 196
Reporting of weather modification activities to the Federal
Government 197
The National Weather Modification Policy Act of 1976 198
Congressional direction to the Bureau of Reclamation 201
Proposed Federal legislation on weather modification 203
Summary 203
Legislation proposed in the 94th Congress and the 95th
Congress, 1st sessions 205
Other congressional activities 207
Resolutions on weather modification 207
Hearings 208
Studies and reports by congressional support agencies 209
Activities of the executive branch 209
Introduction 209
Institutional structure of the Federal weather modification
program 210
Current status of Federal organization for weather modifica-
tion 210
XII
Pa?e
Federal structure; 1946-57 214
Federal structure; 1958-68 215
Federal structure; 1968-77 216
Future Federal organization for weather modification 216
Coordination and advisory mechanisms for Federal weather
modification programs 221
Introduction 221
The Interdepartmental Committee for Atmospheric Sciences
(ICAS) 222
The National Academy of Sciences/Committee on At-
mospheric Sciences (NAS/CAS) 226
The National Advisory Committee on Oceans and Atmos-
phere (NACOA) 227
Other coordination and advisory mechanisms 228
Weather Modification Advisory Board 231
Weather modification activities reporting program 232
Background and regulations 232
Reporting of Federal activities 233
Summary reports on U.S. weather modification activities 233
Federal studies and reports on weather modification 234
Introduction 234
Studies of the early 1950’s 235
Advisory Committee on Weather Control 236
National Academy of Sciences studies 237
Studies by the Interdepartmental Committee for Atmos-
pheric Sciences (ICAS) 238
Domestic Council study 239
Policy and planning reports produced by Federal agencies 239
Federal programs in weather modification 241
Introduction and funding summaries 241
Department of the Interior 246
Introduction 246
Project Sky water; general discussion 247
The Colorado River Basin Pilot Project (CRBPP) 254
The High Plains Cooperative Program (HIPLEX) 258
The Sierra Cooperative Pilot Project (SCPP) 263
Drought mitigation assistance 266
National Science Foundation 267
Introduction and general 267
Weather hazard mitigation 274
Weather modification technology development 282
Inadvertent weather modification 283
Societal utilization activities 2S7
Agricultural weather modification 288
Department of Commerce 290
Introduction and general discussion 290
The Florida Area Cumulus Experiment (FACE) 292
Project Stormfury 296
Research Facilities Center (RFC) 300
Global Monitoring for Climatic Change (GMCC) 301
Lightning suppression 302
Modification of extratropical severe storms 302
Department of Defense 303
Introduction 303
Air Force fog dispersal operations 303
Army research and development 304
Navy research and development 304
Air Force research and development 305
Overseas operations 307
Department of Transportation 308
Department of Agriculture 309
Department of Energy 310
XIII
Chapter 6
Review of recommendations for a national program in weather modifica-
tion
Introduction
Summaries of major weather modification reports
Final report of the Advisory Committee on Weather Control
Weather and climate modification: Report of the Special Com-
mission on Weather Modification
Weather and climate modification: Problems and prospects
A recommended national program in weather modification — ;
A national program for accelerating progress in weather modifica-
tion
Weather and climate modification: Problems and progress
Annual reports to the President and Congress by NACOA
Need for a national weather modification research program
The Federal role in weather modification
Trends and analysis
Page
313
313
314
314
315
317
318
320
321
323
324
325
326
Chapter 7
State and local activities in weather modification 331
Overview of State weather modification activities 331
Introduction 331
North American Interstate Weather Modification Council 333
Survey and summary of State interests and activities in weather
modification 340
State contacts for information on weather modification activities. 343
Non-Federal U.S. weather modification activities 343
Analysis of calendar year 1975 projects 344-
Preliminary analysis of projects for calendar years 1976-77. 347
General discussion of local and regional weather modification policy
activities 348
Weather modification activities within particular States 351
California 352
State weather modification law and regulations 352
Weather modification projects 353
State-sponsored emergency projects 356
Illinois 358
Illinois weather modification law and its administration 35S
Operational projects 359
Research activities 360
Kansas 361
Kansas Weather Modification Act 361
Research activities 362
Operational activities 364
Emergency Drought Act of 1977 304
North Dakota 365
Weather modification law and administration of regulations. 365
Authority and organization for local projects 370
North Dakota operational projects in 1975 and 1976 371
South Dakota 376
Utah 381
Washington 382
Chapter 8
Private activities in weather modification 385
Introduction 385
Commercial weather modifiers 386
Scope and significance of contract activities 386
Summary of contract services 386
Evaluation and research by commercial firms 388-
Participation in Federal research programs 389
Weather modification organizations 389
Professional organizations 389
Weather Modification Association 390
American Meteorological Society 395
XIV
Page
Opposition to weather modification 399
General discussion 399
Opposition to the seeding project above Hungry Horse Dam. 399
Tri-State Natural Weather Association 400
Citizens for the Preservation of Natural Resources 402
Chapter 9
Foreign activities in weather modification 405
Introduction 405
World Meteorological Organization register of weather modification
projects 408
Description of weather modification activities in some foreign nations. 412
The Union of Soviet Socialist Republics 412
Overview of projects in the U.S.S.R 412
Summary of weather modification and related atmospheric
research in the U.S.S.R 413
Israel 415
Australia 416
Canada 418
Mexico 419
People’s Republic of China 420
Kenya 421
Republic of South Africa 422
Rhodesia 423
India 423
The Swiss hail experiment 424
Chapter 10
International aspects of weather modification 427
Introduction 427
Convention on the prohibition of military or any other hostile use of
environmental modification techniques 429
Development of the treaty 429
Criticism of the convention 431
Activities since the United Nations approval of the convention.. 432
Activities of the World Meteorological Organization in weather
modification 433
Precipitation enhancement program (PEP) 434
Other WMO activities in weather modification 436
Registration and reporting of weather modification projects. 436
WMO conferences on weather modification 436
Typhoon and serious storm modification 437
Global atmospheric research programme 437
Legal aspects of weather modification 437
United Nations Conference on the Human Environment 438
Declaration of the United Nations Conference on the Human
Environment 438
Action Plan for the Human Environment 438
Earthwatch Program 439
Study of Man’s Impact on Climate 439
Other international activities 440
United States/ Canadian agreement 440
North American Interstate Weather Modification Council 440
Congressional activities 441
Weather modification as a weapon of war 441
Senate Resolution 71, prohibiting environmental modification
as a weapon of war 441
Congressional activities related to hostile use of weather
modification, 1974-76 442
Other Congressional actions relating to weather modification 443
Senate Concurrent Resolution 67 — U.S. participation in the
world weather program 443
National Weather Modification Policy Act of 1976 444
Senate Resolution 49 444
XV
Page
U.S. foreign policy 444
Various executive branch proposals 445
National Advisory Committee on Oceans and Atmosphere 447
Activities in 1977 448
Chapter 11
Legal aspects of weather modification 449
Domestic 449
Private rights in the clouds 449
Liability for weather modification 453
Defenses which may be raised against claims of liability 456
Interstate allocation of atmospheric water 457
Methods of controlling weather modification 459
Congressional authority under the Constitution to regulate or
license weather modification activities 461
Federalism 461
The commerce clause 461
The commerce clause generally 462
The commerce clause and the regulation of navigable
waters 463
Limitations on the commerce power 464
Fiscal powers 465
War powers 466
Property power 466
Treaty power 467
Conclusion 467
International 468
Certain hostile uses of weather modification are prohibited 471
Nations are responsible for environmental conduct which causes
injury or damage in or to other nations 471
Nations are liable for injuries sustained by aliens within their
territory caused by tortuous conduct in violation of inter-
national law 472
Nations or their citizens may be liable for injury and damage
they caused to citizens of another nation occurring in that
nation 472
Chapter 12
Economic aspects of weather modification : 475
Introduction 475
Economic setting 476
Economic aspects of weather modification procedures 477
Fog dispersal 477
Precipitation augmentation 478
Orographic cloud seeding 478
Convective cloud seeding 478
Precipitation augmentation and energy considerations 479
Hail suppression 480
Lightning suppression and reduction in storm damage 480
Analytic methods for economic analysis 481
Case studies of the economics of weather modification 482
Hungry Horse Area, Montana 482
Connecticut River basin 483
State of Illinois 483
Nine-county Southeastern Crop Reporting District, South Dakota. 483
Colorado River 484
Conclusions 486
Chapter 13
Ecological effects of weather modification 487
Introduction 487
Modification of weather and climate 487
Ecology and ecological systems — 487
Knowledge of ecological implications of applied weather modifi-
cation technologies 488
XVI
Page
Important variables 490
Temporal considerations 491
Season of modification effort 491
Duration of effort: Short- v. long-term 491
Regularity of modification effort 491
Ecosystem type 492
Aquatic v. terrestrial systems 492
Cultivated v. natural systems 492
Arid v. humid systems 492
Cumulative and synergistic effects 492
Effects of silver iodide 493
Deliberate weather modification 496
Precipitation enhancement 496
Increased rainfall 496
Snowpack augmentation 497
Severe storm abatement 498
Fog dispersal 499
Hail suppression 499
Alteration or arrest of lightning discharges 499
Inadvertent weather modification 499
Extra-area effects 499
Long-term, climatic, and global implications 500
Summary and conclusions 501
Appendixes
A. Statement on weather modification in Congressional Record of
June 17, 1975, by Congressman Gilbert Glide, containing White
House statement on Federal weather modification policy 503
B. Department of Defense statement on position on weather modification. 509
C. Text of United Nations Convention on the prohibition of military
or any other hostile use of environmental modification techniques 510
D. State statutes concerning weather modification 514
Arizona 515
California 516
Colorado 520
Connecticut 528
Florida 529
Hawaii 531
Idaho 531
Illinois 533
Iowa 541
Kansas 543
Louisiana 549
Minnesota 550
Montana 554
Nebraska 557
Nevada 565
New Hampshire 571
New Mexico 571
New York 573
North Dakota 573
Oklahoma 584
Oregon 591
Pennsylvania 599
South Dakota 604
Texas 000
Utah 612
Washington 613
West Virginia 618
Wisconsin 622
Wyoming 022
E. List of State contacts for further information on weather modification
activities within the States — 625
F. Agreement on exchange of information on weather modification
between the United States of America and Canada 027
XVII
G. Weather modification activities in the United States during calendar
year 1975
H. Selected bibliography of publications in weather modification
I. Public laws dealing specifically with weather modification
J. Summary of language in congressional
works appropriations for the Bureau
water resources program
K. Membership and charter of the U.S. Department of Commerce
Weather Modification Advisory Board
L. Rules and regulations and required forms for submitting information
on weather modification activities to the National Oceanic and
Atmospheric Administration, U.S. Department of Commerce, in
accordance with requirements of Public Law 92-205
M. Selected State rules and regulations for the administration of State
weather modification statutes
Illinois
Kansas
North Dakota
Utah
Washington
N. Documents of the Weather Modification Association
O. Policy statement of the American Meteorological Society on purposeful
and inadvertent modification of weather and climate
P. Reporting agencies of member countries and questionnaire circulated
to receive weather modification information from members of the
World Meteorological Organization
Q. Report of the World Meteorological Organization/United Nations
Environment programme informal meeting on legal aspects of
weather modification
R. Text of Senate Resolution 71; considered, amended, and agreed to
July 11, 1973
S. Reported cases on weather modification
T. Glossary of selected terms in weather modification
documents supporting public
of Reclamation’s atmospheric
Pa?e
630
641
646
655
660
662
676
676
683
691
707
712
717
722
724
727
734
740
741
34 - 857—79 2
SUMMARY AND CONCLUSIONS
T^eat her modification is generally considered to be the deliberate
effort to improve atmospheric conditions for beneficial human pur-
poses — to augment water supplies through enhanced precipitation or
to reduce economic losses, property damages, and deaths through
mitigation of adverse effects of hail, lightning, fog, and severe storms.
Not all weather modification activities, however, have been or can be
designed to benefit everyone, and some intentional operations have
been used, or are perceived to have been used, as a weapon of war
to impede the mobility or tactical readiness of an enemy. Further-
more, environmental change is also effected unintentionally and with-
out any purpose at all, as man inadvertently modifies the weather and
climate, whether for better or worse scientists are not certain, through
activities such as clearing large tracts of land, building urban areas,
and combustion of fossil fuels.
Historically, there have been attempts, often nonscientific or pseudo-
scientific at best, to change the weather for man's benefit. Until the
20th century, however, the scientific basis for such activities was
meager, with most of our current understanding of cloud physics and
precipitation processes beginning to unfold during the 1930’s. The
modern period in weather modification is about three decades old, dat-
ing from events in 1946, when Schaefer and Langmuir of the General
Electric Co. demonstrated that a cloud of supercooled water droplets
could be transformed into ice crystals when seeded with dry ice. Soon
afterward it was discovered that fine particles of pure silver iodide,
with crystal structure similar to that of ice, were effective artificial
ice nuclei, and that seeding clouds with such particles could produce
ice crystals at temperatures just below freezing. Silver iodide remains
the most often used material in modern “cloud seeding.”
By the 1950’s, many experimental and operational weather modifi-
cation projects were underway; however, these early attempts to
augment precipitation or to alter severe storm effects were often in-
conclusive or ineffective, owing to improper experimental design, lack
of evaluation schemes, and the primitive state of the technology.
Through research programs over the past two decades, including
laboratory studies and field experiments, understanding of atmos-
pheric processes essential to improved weather modification tech-
nology has been advanced. Sophisticated evaluation schemes have been
developed, using elaborate statistical tools; there has also been im-
provement in measuring instruments and weather radar systems ; and
simulation of weather processes using numerical models and high
speed computers has provided further insights. Meanwhile, commer-
cial weather modifiers, whose number decreased dramatically along
with the total area of the United States covered by their operations
after the initial surge of the 1950 era, have grown in respectability and
competence, and their operations have incorporated improvements as
they benefited from their accumulated experience and from the re-
(XIX)
XX
suits of research projects. Since such operations are designed for prac-
tical results, such as increased precipitation or reduced hail, however,
the sophisticated evaluation procedures now used in most research
projects are most often not used, so that the effectiveness of the opera-
tions is frequently difficult to assess.
Weather modification is at best an emerging technology. Progress in
development of the technology over the past 30 years has been slow,
although there has been an increased awareness of the complex nature
of atmospheric processes and a steady improvement in basic under-
standing of those processes which underlie attempts at deliberate modi-
fication of weather phenomena. Though most cloud-seeding practices
are based on a common theory and form the basis for a number of seed-
ing objectives, there are really a series of weather modification
technologies, each tailored to altering a particular atmospheric pheno-
menon and each having reached a different state of development and
operational usefulness. For example, cold fog clearing is now consid-
ered to be operational, while, at the other extreme, the abatement of
severe storms such as hurricanes remains in the initial research phase.
Development progress for each of these technologies appears to be
much less a function of research effort expended than a dependence on
the fundamental atmospheric processes and the ease by which they can
be altered. There continues to be obvious need for further research and
development to refine those few techniques for which there has been
some success and to advance technology where progress has been slow
or at a virtual standstill.
The following summary provides a reasonably accurate assessment
of the current status of weather modification technology :
1. The only routine operational projects are for clearing cold fog.
Research on warm fog has yielded some useful knowledge and good
models, but the resulting technologies are so costly that they are usable
mainly for military purposes and very busy airports.
2. Several longrunning efforts to increase winter snowpack by seed-
ing clouds in the mountains suggest that precipitation can be increased
by some 15 percent over what would have happened “naturally.”
3. A decade and a half of experience with seeding winter clouds on
the U.S. west coast and in Israel, and summer clouds in Florida, also
suggest a 10- to 15-percent increase over “natural” rainfall. Hypotheses
and techniques from the work in one area are not directly transferable
to other areas, but will be helpful in designing comparable experiments
with broadly similar cloud systems.
4. Numerous efforts to increase rain by seeding summer clouds in the
central and western parts of the United States have left many questions
unanswered. A major experiment to try to answer them — for the High
Plains area — is now in its early stages.
5. It is scientifically possible to open holes in wintertime cloud layers
by seeding them. Increasing sunshine and decreasing energy consmp-
tion may be especially relevant in the northeastern quadrant of the
United States.
6. Some $10 million is spent by private and local public sponsors for
cloud-seeding efforts, but these projects are not designed as scientific
experiments and it is difficult to say for sure that operational cloud
seeding causes the claimed results.
XXI
7. Knowledge about hurricanes is improving with good models of
their behavior. But the experience in modifying that behavior is primi-
tive so far. It is inherently difficult to find enough test cases, especially
since experimentation on typhoons in the Western Pacific has been
blocked for the time being by international political objections.
8. Although the Soviets and some U.S. private operators claim some
success in suppressing hail by seeding clouds, our understanding of the
physical processes that create hail is still weak. The one major U.S.
Held experiment increased our understanding of severe storms, but
otherwise proved mostly the dimensions of what we do not yet know.
9. There have been many efforts to suppress lightning by seeding
thunderstorms. Our knowledge of the processes involved is fair, but the
technology is still far from demonstrated, and the U.S. Forest Service
has recently abandoned further lightning experiments. 1
Modification processes may also be initiated or triggered inadvert-
ently rather than purposefully, and the possibility exists that society
may be changing the climate through its own actions by pushing on
ceitain leverage points. Inadvertently, man is already causing measur-
able variations on the local scale. Artificial climatic effects have been
observed and documented on local and regional scales, particularly in
and dovmwind of heavily populated industrial areas where waste heat,
particulate pollution and altered ground surface characteristics are
primarily responsible for the perceived climate modification. The cli-
mate in and near large cities, for example, is warmer, the daily range
of temperature is less, and annual precipitation is greater than if the
cities had never been built. Although not verifiable at present, the time
may not be far off when human activities will result in measurable
large-scale changes in weather and climate of more than passing sig-
nificance. It is important to appreciate the fact that the role of man at
this global level is still controversial, and existing models of the gen-
eral circulation are not yet capable of testing the effects in a conclusive
manner.
Nevertheless, a growing fraction of current evidence does point to
the possibility of unprecedented impact on the global climate by hu-
man activities, albeit the effects may be occurring below the threshold
where they could be statistically detected relative to the record of nat-
ural fluctuations and. therefore, could be almost imperceptible amid
the ubiquitous variability of climate. But while the degree of influence
on world climate may as yet be too small to detect against the back-
ground of natural variations and although mathematical models of
climatic change are still imperfect, significant global effects in the
future are inferred if the rates of growth of industry and population
persist.
For over 30 years both legislative and executive branches of the
Federal Government have been involved in a number of aspects of
weather modification. Since 1947 about 110 weather modification bills
pertaining to research support, operations, grants, policy studies, regu-
lations, liabilities, activity reporting, establishment of panels and com-
mittees, and international concerns have been introduced in the Con-
1 Weather Modification Advisory Board. “A U.S. Policy to Enhance the Atmospheric
Environment,” Oct. 21, 1977. In testimony by Harlan Cleveland, Weather modification.
Hearing before the Subcommittee on the Environment and the Atmosphere, Committee on
Science and Technology. U.S. House of representatives, 95th Cong., 1st sess., Oct. 20,
1977, Washington, U.S. Government Printing Office, 1977. pp. 28-30.
XXII
gress. Resolutions, mostly concerned with using weather modification
as a weapon and promotion of a United Nations treaty banning such
activities, have also been introduced in both houses of the Congress;
one such resolution was passed by the Senate.
Six public laws specifically dealing with weather modification have
been enacted since 1953, and others have included provisions which are
in some way relevant to weather modification. Federal weather modi-
fication legislation has dealt primarily with three aspects — research
program authorization and direction, collection and reporting of in-
formation on weather modification activities, and the commissioning
of major policy studies. In addition to direction through authorizing
legislation, the Congress initiated one major Federal research pro-
gram through a write-in to an appropriations bill; this program
regularly receives support through additional appropriations beyond
recommended OMB funding levels.
There are two Federal laws currently in effect which are specifically
concerned with weather modification. Public Law 92-205, of Decem-
ber 18, 1971, and its amendments requires the reporting of all non-
Federal activities to the Secretary of Commerce and publication “from
time to time” of summaries of such activities by the Secretary of’
Commerce. 2 The National Weather Modification Policy Act of 197G
(Public Law 94-490), enacted October 13, 1976, directed the Secretary
of Commerce to conduct a major study on weather modification and to
submit a report containing a recommended Federal policy and Fed-
eral research program on weather modification. The Secretary ap-
pointed a non-Government Weather Modification Advisory Board to
conduct the mandated study, the report on which is to be submitted
to the Secretary for her review and comment and subsequent trans-
mittal to the President and the Congress during 1978. It is expected
that, following receipt of the aforementioned report, the Congress will
consider legislation on Federal weather modification policy, presuma-
bly during the 96th Congress.
Congressional interest in weather modification has also been mani-
fested in a number of hearings on various bills, in oversight hearings
on pertinent ongoing Federal agency programs, in consideration of
some 22 resolutions having to do with weather modification, and in
commissioning studies on the subject by congressional support
agencies.
The principal involvement in weather modification of the Federal
Government has been through the research and development programs
of the several Federal departments and agencies. Although Federal
research programs can be traced from at least the period of World
War II, the programs of most agencies other than the Defense Depart-
ment were not begun until the 1950’s and 1960’s. These research and
development programs have been sponsored at various times by at
least eight departments and independent agencies — including the De-
partments of Agriculture, Commerce, Defense, Energy, Interior, and
Transportation, the National Aeronautics and Space Administration
(NASA), and the National Science Foundation (NSF). In fiscal year
2 Although Federal nuncios were excluded from the requirements of this net. upon
mutual agreement, the jipeneies also submit information on their weather modification
projects to t lie Secretary of Commerce, so that there is a single repository for information
on all weather modification activities conducted within the United States.
XXIII
1978 six agency programs were reported, those of Transportation and
NASA having been phased out, while that of Agriculture was severely
curtailed.
Total funding for Federal weather modification research in fiscal
year 1978 is estimated at about $17 million, a decline from the highest
funding level of $20 million reached in fiscal year 1976. The largest
programs are those of the Departments of Interior and Commerce and
of the NSF. The NSF has supported weather modification research
over a broad spectrum for two decades, although its fiscal year 1978
funding was reduced by more than 50 percent, and it is not clear that
more than the very basic atmospheric science supportive of weather
modification will be sponsored hereafter by the Foundation.
The present structure of Federal organization for weather modifi-
cation research activities is characterized essentially by the mission-
oriented approach, whereby each of the agencies conducts its own
program in accordance with broad agency goals or under specific direc-
tions from the Congress or the Executive. Programs have been loosely
coordinated through various independent arrangements and/or advi-
sory panels and particularly through the Interdepartmental Commit-
tee for Atmospheric Sciences (ICAS). The ICAS, established in 1959
by the former Federal Council for Science and Technology, provides
advice on matters related to atmospheric science in general and has
also been the principal coordinating mechanism for Federal research
in weather modification.
In 1958 the National Science Foundation was designated lead agency
for Federal weather modification research by Public Law 85-510, a
role which it maintained until 1968, when Public Law 90-407 removed
this responsibility from NSF. No further action was taken to name a
lead agency, although there have been numerous recommendations to
designate such a lead agency, and several bills introduced in the Con-
gress would have named either the Department of the Interior or the
Department of Commerce in that role. During the 10-year period from
1958 to 1968 the NSF promoted a vigorous research program through
grants to various research organizations, established an Advisory
Panel for Weather Modification, and published a series of 10 annual
reports on weather modification activities in the United States. Since
1968 there has been a lapse in Federal weather modification policy and
in the Federal structure for research programs, although, after a
hiatus of over 3 years, the responsibility for collecting and disseminat-
ing information on weather modification activities was assigned to the
Commerce Department in 1971. An important consideration of any
future weather modification legislation will probably be the organiza-
tional structure of the Federal research program and that for admin-
istration of other related functions which may be the responsibility of
the Federal Government. Options include a continuation of the present
mission-oriented approach with coordination through the ICAS or a
similar interagency body, redesignation of a lead agency with some
autonomy remaining with the several agencies, or creation of a single
agency with control of all funding and all research responsibilities.
The latter could be an independent agency or part of a larger depart-
ment; it would presumably also administer other aspects of Federal
weather modification responsibilities, such as reporting of activities,
XXIV
regulation and licensing, and monitoring and evaluation of operations,
if any or all of these functions should become or continue to be services
performed at the Federal level.
In addition to specific research programs sponsored by Federal agen-
cies, there are other functions related to weather modification which
are performed in several places in the executive branch. Various Fed-
eral advisory panels and committees and their staffs — established to
conduct in-depth studies and prepare comprehensive reports, to pro-
vide advice and recommendations, or to coordinate Federal weather
modification programs — have been housed and supported within exec-
utive departments, agencies, or offices. The program whereby Federal
and non-Federal U.S. weather modification activities are reported to
the Government is administered by the National Oceanic and Atmos-
pheric Administration (NOAA) within the Commerce Department.
The State Department negotiates agreements with other nations which
might be affected bv IT.S. experiments and has arranged for Federal
agencies and other U.S. investigators to participate in international
meteorological projects, including those in weather modification. In
the United Nations, the United States has been active in promoting the
adoption of a treaty banning weather modification as a military
weapon.
In accordance with the mandates of several public laws or self-ini-
tiated by the agencies or interagency committees, the executive branch
of the Federal Government has undertaken a number of major weather
modification policy studies over the past 25 years. Each of the com-
pleted major studies was followed by a report which included findings
and recommendations. The most recent study is the one noted earlier
that is being conducted by the Weather Modification Advisory Board
on behalf of the Secrctarv of Commerce, pursuant to requirements of
the National Weather Modification Policy Act of 1976. Nearly all
previous studies emphasized the needs for designation of a lead agency,
increased basic meteorological research, increased funding, improve-
ment of support and cooperation from agencies, and consideration of
legal, socioeconomic, environmental, and international aspects. Other
recommendations have included improvement of program evaluation,
studv of inadvertent effects, increased regulation of activities, and a
number of specific research projects. Although some of the recom-
mended activities have been undertaken, many have not resulted in
specific actions to date. Almost invariably it was pointed out in the
studies that considerable progress would result from increased fund-
ing. Although funding for weather modification research has increased
over the past 20 years, most funding recommendations have been for
considerably higher levels than those provided. Since fiscal year 1976,
the total Federal research funding for weather modification research
lias, in fact, decreased.
Most States in the Nation have some official interest in weather
modification ; 29 of them have some form of law which relates to such
activities, usually concerned with various facets of regulation or con-
trol of operations within the State and sometimes pertaining to au-
thorization for funding research and/or operations at the State or
local level. A State’s weather modification law usually reflects its gen-
eral policy toward weather modification; some State laws tend to en-
XXV
courage development and use of the technology, while others dis-
courage such activities.
The current legal regime regulating weather modification has been
developed by the States rather than the Federal Government, except
in the areas of research support, commissioning studies, and requiring
reporting of activities. The various regulatory and management func-
tions which the States perform include: (1) issuance, renewal, sus-
pension, and revocation of licenses and permits; (2) monitoring and
collecting of information on activities through requirements to main-
tain records, submission of periodic activity reports, and inspection
of premises and equipment; (3) funding and managing of State or
locally organized operational and/or research programs ; (4) evalua-
tion and advisory services to locally organized public and private op-
erational programs within the State; and (5) miscellaneous admin-
istrative activities, including the organization and operation of State
agencies and boards which are charged with carrying out statutory
responsibilities. Administration of the regulatory and managerial re-
sponsibilities pertaining to weather modification within the States is
accomplished through an assortment of institutional structures, in-
cluding departments of water or natural resources, commissions, and
special governing or advisory groups. Often there is a combination of
two or more of these agencies or groups in a State, separating func-
tions of pure administration from those of appeals, permitting, or ad-
visory services.
Involvement in weather modification operational and research pro-
grams varies from State to State. Some support research only, while
others fund and operate both research and operational programs. In
some cases funding only is provided to localities, usually at the county
level, where operational programs have been established. The recent
1976-77 drought led some Western States to initiate emergency cloud-
seeding programs as one means of augmenting diminishing water sup-
plies. Research conducted by atmospheric and other scientists at State
universities or other research agencies may be supported in part with
State funds but is often funded by one of the major Federal weather
modification programs, such as that of the Bureau of Reclamation or
the National Science Foundation. In a few cases. States contribute
funds to a Federal research project which is conducted jointly with
the States and partly within their borders.
In 1975, 1976, and 1977, respectively, there were 58, 61, and 88 non-
federally supported weather modification projects, nearly all opera-
tional, conducted throughout the United States. These projects were
sponsored by community associations, airlines, utilities, private in-
terests, municipal districts, cities, and States. Eighty-five percent of
all projects in the United States during 1975 were carried out west of
Kansas City, with the largest number in California. In that State
there were 11 projects in each of the vears 1975 and 1976, and 20
projects during 1977. The majority of these operational projects were
designed to increase precipitation; others were intended for sup-
pression of hail or dispersal of fogs, the latter principally at airports.
In most instances, the principal beneficiaries of weather modification
are the local or regional users, who include farmers and ranchers,
weather-related industries, municipalities, airports, and utilities —
XXVI
those individuals and groups whose economic well-being and whose
lives and property are directly subject to adverse consequences of
drought or other severe weather. It is at the local level where the need
to engage in weather modification is most keenly perceived and also
where possible negative effects from such activities are most apparent
to some sectors of the population. It follows that both the greatest sup-
port and the strongest opposition to weather modification projects are
focussed at the local level. The popularity of a particular project and
the degree of controversy surrounding it are frequently determined by
the extent to which local citizens and local organizations have had a
voice in the control or funding of the project. At the local level, deci-
sions to implement or to withdraw from a project can most often be
made with minimum social stress. Indeed, studies have shown that most
people are of the opinion that local residents or local government offi-
cials should make decisions on whether or not to use weather modifica-
tion technology in a given situation.
Many of the operational weather modification services provided for
private groups and governmental bodies within the States are carried
out under contract by commercial firms who have developed expertise
in a broad range of capabilities or who specialize in particular services
essential to both operational or research projects. Contracts may cover
only one season of the year, but a number of them are renewed an-
nually, with target areas ranging from a few hundred to a few thou-
sand square miles. In 197G, 6 of the 10 major companies having
substantial numbers of contracts received about $2.7 million for op-
erations in the United States, and a few of these companies also had
contracts overseas. Owing to increased demand for emergency pro-
grams during the recent drought, it is estimated that 1977 contracts
totaled about $3.5 million.
The initial role of the private weather modification operators was to
sustain activities during the early } 7 ears, when there was often heated
scientific controversy with other meteorologists over the efficacy of
cloud seeding. Later, their operations provided a valuable data base
which permitted the early evaluation of seeding efforts and estimates
of potential prospects for the technology, meanwhile growing in com-
petence and public respect. Today, more often than not, they work
hand in hand with researchers and, in fact, they often participate in
research projects, contributing much of their knowhow acquired
through their unique experiences.
Important among private institutions concerned with weather modi-
fication are the professional organizations of which research and op-
erational weather modifiers and other interested meteorologists are
members. These include the American Meteorological Society, the
Weather Modification Association, and the Irrigation and Drainage
Division of the American Society of Civil Engineers. Through the
meetings and publications of these organizations the scientific, tech-
71 ical, and legal problems and findings on weather modification are
aired and discussed. These groups also address other matters such as
statements of weather modification policy, opinions on pending legis-
lation, social implications, and professional standards and certifica-
tion. In addition, the North American Interstate Weather Modifica-
tion Council is an organization whose membership consists of govern-
XXVII
ments of U.S. States and Canadian Provinces and the Government of
Mexico, which serves as a forum for interstate coordination and ex-
change of information on weather modification.
Weather modification is often controversial, and both formal and
informal opposition groups have been organized in various sections
of the country. Reasons for such opposition are varied and are based
on both real and perceived adverse consequences from weather modifi-
cation. Sometimes with little or no rational basis there are charges
by these groups that otherwise unexplained and usually unpleasant
weather- related events are linked to cloud seeding. There are also cases
where some farmers are economically disadvantaged through receiving
more, or less than optimum rainfall for their particular crops, when
artificial inducement of such conditions may have indeed been planned
to benefit those growing different crops with different moisture re-
quirements. Opposition groups are often formed to protect the legiti-
mate rights of farmers under such circumstances.
While the United States is the apparent leader in weather modifi-
cation research and operations, other countries have also been active.
Information on foreign weather modification activities is not uni-
formly documented and is not always available. In an attempt to
assemble uniform weather modification activities information of its
member nations, the World Meteorological Organization (WMO) in
1975 instigated a system of reporting and of maintaining a register on
such activities. Under this arrangement 25 nations reported weather
modification projects during 1976, and 16 countries provided similar
information in 1975. The largest weather modification effort outside
the United States is in the Soviet Union, where there are both a con-
tinuing research program and an expanding operational program. The
latter is primarily a program designed to reduce crop damage from
hail, the largest such effort in the world, covering about 5 million
hectares (15 million acres) in 1976. Other countries with weather modi-
fication programs of some note include Canada, Israel, Mexico, and
the People’s Republic of China. Projects in Rhodesia and the Republic
of South Africa are not reported through the WMO register since
these countries are not WMO member nations.
Recent years have seen increased international awareness of the
potential benefits and possible risks of weather modification technology
and increased international efforts to control such activities. The major
efforts of the international community in this area are to encourage
and maintain the high level of cooperation which currently exists in
weather prediction and research and to insure that man’s new abilities
will be used for peaceful purposes. There has been exchange of ideas
on weather modification through international conferences and
through more informal exchanges of scientists and research documents.
As with many scientific disciplines, however, the problems arising
from use of and experiments with weather modification are not just
scientific in nature, but are political problems as well.
In addition to the problems of potential damage to countries through
commercial or experimental weather modification activities, another
growing area of concern is that weather modification will be used for
hostile purposes and that the future will bring weather warfare be-
tween nations. The United States has already been involved in one
XXVIII
such instance during the Vietnam war when attempts were made to
impede traffic by increasing rainfall during the monsoon season. In the
future, even the perception that weather modification techniques are
available or in use could lead to an increase in international tensions.
Vat ura 1 drought in a region, or any other natural disaster will be
suspect or blamed on an enemy.
In light of these problems the international community has made
scattered attempts both to further the study of weather and its modifi-
cation and to insure the peaceful use of this new technology. One such
attempt was the development of the Convention on the Prohibition
of Military or Any Other Hostile Use of Environmental Modification
Techniques, which was adopted by the General Assembly of the United
Nations and opened for signature on May 18. 1977, at which time it was
signed by the United States and 33 other nations (though it has not
yet been submitted to the U.S. Senate for ratification) . Another exam-
ple of promotion of peaceful use of weather modification is the Pre-
cipitation Enhancement Program, sponsored by the WMO, whose aim
is to plan, set up, and carry out an international, scientifically con-
trolled precipitation experiment in a semiarid region of the world
under conditions where the chances are optimal for increasing pre-
cipitation in sufficient amounts to produce economic benefits.
The United Nations Conference on the Human Environment, held
in June 1972 in Stockholm, has been the pivotal point in much recent
international environmental activity. It too has been an important
catalyst in international activities relating to weather modification
through portions of its “Declaration,” its “Action Plan for the Human
Environment,” its “Earthwatch Program,” and its “Study of Man's
Impact on Climate.”
Legal issues in weather modification are complex and unsettled.
They can be considered in at least four broad categories : private rights
in the clouds, liability for weather modification, interstate legal issues,
and international legal issues. Since the body of law on weather modi-
fication is slight, existing case law offers few guidelines to determine
these issues. Begarding the issue of private rights in the clouds, there
is no general statutory determination of ownership of atmospheric
water, so it is often necessary to use analogies to some general common
law doctrines pertaining to water distribution, although each such
doctrine has its own disadvantages when applied to weather modifica-
tion. Some State laws reserve ownership or right to use atmospheric
water to the State.
Issues of liability for damage may arise when drought, flooding
or other severe weather phenomena occur following attempts to modify
the weather. Such issues include causation, nuisance, strict liability,
trespass, negligence, and charges of pollution of the air and water
through introduction of artificial nucleants. Statutes of 10 States dis-
cuss weather modification liability; however, there is much variation
among the specific provisions of the laws in those States. Before a
case can be made for liability based on causation, it must be proven
that the adverse weather conditions were indeed induced by the weather
modifier; but, in fact, no one has ever been able to establish causation
of damages through such activities in view of the scientific uncer-
tainties of weather modification.
XXIX
Significant issues may arise when weather modification activities
conducted in one State affect another State as well. There may be, for
example, the claim that seeding in one State has removed from the
clouds water that should have fallen in an adjacent State or that
excessive flooding resulted from cloud seeding in a State upwind.
Operation of cloud-seeding equipment near the border of one State
may also violate local or State regulations or prohibitions of such
operations in that State. There have been some attempts to resolve these
and other issues through specific legislation in some States and through
informal bilateral agreements. While no formal compacts currently
exist, some compacts allocating waters in interstate streams may be
applicable.
Because atmospheric processes operate independent of national
borders, weather modification is inherently of international concern,
and, international legal issues have similarities to domestic interstate
activities and dangers. Whereas domestic weather modification law is
confused and unsettled, international law in this area is barely in the
formative stage. In time, ramifications of weather modification may
lead to major international controversy.
Whereas the potential for long-term economic gains through weather
modification cannot be denied, current economic analyses are tenuous in
view of present uncertainty of the technology and the complex nature
of attendant legal and economic problems. Economic evaluation of
weather modification activities has therefore been limited to special,
localized cases, such as the dispersal of cold fog at airports, where
benefit-cost ratios greater than 5 to 1 have been realized through sav-
ings in delayed or diverted traffic. It has also been estimated, on the
basis of a 15-percent increase in snowpack through seeding orographic
clouds, that about 2 million additional acre-feet of water per year
could be produced in the Colorado River Basin, at a cost of about
$1.50 per acre-foot.
Costs of most weather modification operations are generally small
in i-elation to other costs in agriculture, for example, and are normally
believed to be only a fraction of the benefits which could be achieved
from successful operations. However, if all the benefits and all the costs
are considered, benefit-cost ratios may be diminished. While direct costs
and benefits from weather modification are reasonably apparent, in-
direct costs and benefits are elusive and require further study of
sociological, legal, and ecological implications.
There are numerous cases of both real and perceived economic losses
which one or more sectors of the public may suffer while another
group is seeking economic advantage through some form of weather
modification. Overall benefits from weather modification are accord-
ingly reduced when net gains are determined from such instances of
mixed economic advantages and disadvantages. In fact, when mecha-
nisms are established for compensating those who have suffered losses
resulting from weather modification, benefits to those groups seeking
economic gain through such projects will probably be accordingly
reduced.
Economically significant weather modification activities will have
an eventual ecological effect, though appearance of that effect may be
hidden or delayed by system resilience and/or confused by system
XXX
complexity. Prediction of ecological effects may never be possible with
any precision; however, the greater the precision with which the
weather modifier can predict results of his activities, the more pre-
cisely can the ecologist predict ecological effects. Such effects will
rarely be sudden or catastrophic, but will result from moderate
weather-related shifts in rates of reproduction, growth, and mortality
of plants and animals. Adjustments of plant and animal communities
will thus occur more slowly in regions of highly variable weather than
in those with more uniform conditions which are slowly changing with
some regularity over time. Deliberate weather modification, such as
precipitation augmentation, is likely to have a greater ecological im-
pact in semi-arid regions than in humid ones.
Widespread cloud seeding, using silver iodide, could result in esti-
mated local, temporary increases in silver concentrations in precipita-
tion approaching those in natural waters, but exchange rates would be
an order of magnitude lower than the natural exchange rates. Ex-
change rates will likely be many orders of magnitude less than those
rates at which plants and soils are adversely affected.
Conclusions
1. Weather modification is an emerging technology; there is a wide
spectrum of capabilities to modify various weather phenomena, rang-
ing from the operational readiness of cold fog dispersal to little prog-
ress beyond initial research in the case of modifying severe storms
such as hurricanes.
2. Along with cold fog dispersal, the only other weather modifica-
tion capability showing near readiness for application is the aug-
mentation of winter snowpack through seeding mountain cloud sys-
tems. A probable increase of about 15 percent is indicated by a number
of experiments and longrunning operational seeding projects in the
western United States.
3. Most scientists and weather modification operators agree that
there is continued need for a wide range of research and development
activity both to refine weather modification techniques where there
has been some success and to advance capabilities in modifying other
weather phenomena where there has been much less or little progress.
4. Current Federal policy for weather modification research and
development follows the mission-oriented approach, where each agency
charged with responsibility for dealing with a particular national
problem is given latitude to seek the best approach or solution to the
problem; this approach or solution may involve weather modification.
5. The structure of Federal organization for weather modification
reflects the mission-oriented approach which is characteristic of the
current Federal policy, the programs loosely coordinated through ad-
visory groups and the Interdepartmental Committee for Atmospheric
Sciences.
0. The interest of the Congress in weather modification has been
shown by the introduction of 110 bills related to the subject since
1047 — (5 of which have become public law — and the consideration of 22
resolutions on weather modification, one of which was passed by the
Senate.
7. A number of major weather modification policy studies have been
directed by public law or initiated within the executive branch over
xxxr
the past 25 years; most of these studies recommended designation of
a lead agency, increased basic meteorological research, increased fund-
ing, improvement of support and cooperation from agencies, and con-
sideration of legal, socioeconomic, environmental, and international
aspects. Although some recommended actions have been undertaken,
others have not seen specific action to date.
8. While major policy studies have recommended increased funding
for Federal weather modification, research and development and fund-
ing has generally increased over the past 20 years, recommended levels
have been consistently higher than those provided, and funding has
actually decreased since fiscal year 1976.
9. With enactment of the Xational Weather Modification Policy
Act of 1976 and completion of the major policy study mandated by
that act, there is a fresh opportunity for the Congress to assess the
potential usefulness and problems in application of weather modifica-
tion technology and to establish a new Federal policy for weather
modification research and operations.
10. The principal role in regulating weather modification and in
supporting operational programs has been taken by the States, while
the role of the Federal Government has been support of research and
development programs.
11. The majority of the States (29) have some form of law which
relates to weather modification, and the general policy of a State
toward weather modification is usually reflected in the weather modi-
fication law of that State ; laws of some States tend to encourage devel-
opment and use of the technology, while others discourage such
activities.
12. The majority of operational weather modification projects in the
United States (58 of a total of 72, or 80 percent in calendar year 1975)
are conducted'west of Kansas City, and the largest number of projects
has been in California (20 during 1977) ; most operational projects
are intended to increase precipitation, while others are designed to
suppress hail or disperse fog.
13. Both the greatest support and the strongest opposition to weather
modification projects are focused at the local level, where the economic
and personal interests of local organizations and individuals are most
directly affected; it follows that there is also the least social stress
when decisions to apply or withhold weather modification are made
at the local level.
14. Commercial weather modification operators have substained ac-
tivities since the early days, after which some operations fell into
disrepute, providing a valuable data base for evaluation of long-term
projects and developing expertise over a broad range of capabilities:
most have incorporated improvements into their technology as they
have benefited from accumulated experience and from research results.
15. While the United States is the apparent leader in overall research
and operational weather modification activities, there have been ap-
proximately 20 foreign countries in which activities are conducted an-
nually (25 countries reported such projects for 1976 through the
register of the World [Meteorological Organization) : the largest for-
eign program is that of the Soviet Union, whose operational hail
suppression program covered about 15 million acres in 1976, the largest
such effort in the world.
XXXII
1G. The international community has attempted to further the study
of weather modification and insure its peaceful use through the recent
development of a Convention on the Prohibition of Military or Any
Other Hostile Use of Environmental Techniques (adopted by the
U.X. General Assembly and opened for signature in May 1977) and
through sponsorship by the World Meteorological Organization of
an international precipitation enhancement program.
17. Legal issues in weather modification are complex and unsettled;
they include resolution of problems of ownership of atmospheric water,
issues of liability, conflicting statutes and regulations of respective
State laws, and the need to develop a regime of relevant international
law.
IS. Although the long-term potential for economic gains through
weather modification cannot be denied, attempts to quantify benefits
tmd costs from such activities will in most cases be difficult to undertake
on a practical basis until the technology is more highly developed and
control systems are perfected to permit reliable predictions of
outcomes.
19. Economically significant weather modification will always have
an eventual ecological effect, though appearance of the effect may be
delayed or hidden by system resilience and/or confounded by system
complexity ; the more precisely the weather modifier can specify effects
lie will produce, tire more precise can be the ecologist's prediction of
likely ecological effects.
20. Modification processes may also be initiated or triggered inad-
vertently rather than purposefully ; man is already causing measurable
variations unintentionally on the local scale, and artificial climate
effects have been observed on local and regional scales. Although not
verifiable at present, the time may not be remote when human activities
will result in measurable large-scale changes in weather and climate
of more than passing significance.
CHAPTER 1
INTRODUCTION AND SUMMARY OF ISSUES
(Ry Robert E. Morrison, Specialist in Earth Sciences, Science Policy Research
Division, Congressional Research Service)
Perspective
“It is entirely possible , were he wise enough , that man could produce
favorable effects , perhaps of enormous practical significance , trans-
forming his environment to render it more salutary for his purposes .
This is certainly a matter which should be studied assiduously and
explored vigorously . The first steps are clear. In order to control
meteorological matters at all ice need to understand them better than
we now do. AY hen we understand fully we can at least predict weather
with assurance for reasonable intervals in the future.
‘'With modem analytical devices , with a team of sound background
and high skills , it is possible today to do a piece of work in this field
which will render immediate benefits , and carry us far toward a more
thorough understanding of ultimate possibilities. By all means let us
get at it”
— Yannevar Bush 1
SITUATION
Two decades after completion of a major study and report on
weather modification by the Advisory Committee on Weather Control
and after the assertions quoted above, many would agree that some
of the more fundamental questions about understanding and using
weather modification remain unsolved. There is a great difference of
opinion, however, on the state of technology in this field. According
to Grant, ‘‘Some believe that weather modification is now ready for
widespread application. In strong contrast, others hold that applica-
tion of the technology may never be possible or practical on any
substantial scale.” 2 It has been demonstrated that at least some atmos-
pheric phenomena can be modified with some degree of predictable
success, as a consequence of seeding supercooled clouds with artificial
ice nuclei, and there is some promise that the present technology will
be expanded to include a greater scope of weather modification capa-
bilities. Nevertheless, a systematic approach and reasonable progress
in development of weather modification technology have been impeded
by a number of problems.
Changnon asserts that a continuing and overriding problem restrict-
ing progress has been the attempt to apply an ill-defined technology
to increase rain or suppress hail without an adequate scientific under-
1 From statement of Dec. 2, 1957, quoted in final report of the Advisory Committee on
Weather Control, Washington, D.C., U.S. Government Printing Office. 195S. vol. I, p. 1.
2 Grant, Lewis O., “Scientific and Other Uncertainties of Weather Modification.” In
William A. Thomas (editor). Legal and Scientific Uncertainties of Weather Modification,
Proceedings of a symposium convened at Duke University. Mar 11-12, 1976, by the
National Conference of Lawyers and Scientists, Durham, N.C., Duke University Press,
1977, p. 7.
34-857—79 3
( 1 )
2
standing and predictable outcome . 3 Experimentation has been poorly
conducted, intermittent, or too short; and “results have not been inte-
grated with those of other projects so as to develop a continuing thread
of improving knowledge /’ 4
In response to the query as to why progress in weather modification
has been so slow, Fleagle identifies three broad, general impediments.
“First, the physical processes associated with clouds have turned out to
be especially complex and difficult * * *. A second possibility may be
that the atmosphere is inherently stable, so that within broad limits, no
matter what we do to increase precipitation, the results are likely to be
small and roughly the same * * *. A third reason * * * is that progress
has been hamstrung by fragmentation of resources, by submarginal
funding, ineffective planning and coordination, and a general lack of
administrative toughness and fiscal stability." 5
Droessler points out the need to “formulate a comprehensive national
weather modification policy which has the broad support of the scien-
tific community, the general public, private industry, and the Govern-
ment.*’ contending that “the greatest deterrent in getting on with the
task of preparing a satisfactory national policy is the lack of a con-
sensus about the national goals for weather modification.” 6
Although operational readiness varies from one form of weather
modification to another, as a result of the degree of understanding and
the complexity of decisionmaking in given situations, the prospects for
successful weather modification are sufficiently promising that at-
tempts to develop effective applications will continue. This was one of
the major areas of consensus at a recent symposium on the uncertainties
of weather modification :
There will be increased attempts to modify weather, both because people tend
to do what is technically possible and because the anticipated benefits of precipi-
tation augmentation, hail or lightning suppression, hurricane diversion, and other
activities often exceed the associated costs . 7
With the inevitable increases in weather modification capabilities
and the increasing application of these capabilities, the development of
a technology that is socially useful must be insured through a careful
analysis of attendant benefits and disbenefits. According to Fleagle,
et ah. deliberate efforts to modify the weather have thus far had only
marginal societal impacts: however, as future activities expand, “they
will probably be accompanied by secondary effects which in many
instances cannot be anticipated in detail * * Consequently, “rational
policy decisions are urgently needed to insure that activities are di-
rected toward socially useful goals.” 8
The lack of a capability to deal with impending societal problems
3 Changnon. Stanley A., Jr., “The Federal Hole in Weather Modification.” background
paper prepared for use by the U.S. Department of Commerce Weather Modification Advi-
sory Board. Mar. 0. 1077, p. 5.
4 Ibid., pp. .">-0
5 Fleagle, Robert G.. “An Analysis* of Federal Policies in Weather Modification.” back-
ground paper prepared for use by the U.S. Department of Commerce Weather Modification
Advisory Board. Mar. 1077. pp. 17-1S.
Droessler, Karl G.. “Weather Modification” (Federal Policies. Funding From All
Sources, Interagency Coordination), background paper prepared for use of the U.S. Depart-
ment of Commerce Weather Modification Advisory Board. Mar. 1, 1077. p. 10
7 Thomas. William A. (editor). “l egal and Scientific Uncertainties of Weather Modifica-
tion,” proceedings of a symposium convened at Duke University. Mar. 11 12. 1070. hy the
Xe f, onal Conference of Lawyers and Scientists, Durham, X.C., Duke University Press,
1077, p. vi.
Fleagie. Robert G.. James A. Crntehfield. Ralph W. Johnson, and Mohamed F. Ahdo,
“Weather Modification In the Public Interest.” Seattle. American Meteorological Society
and the University of Washington Press, 1073, p. 3, 31-32.
o
O
ancl emerging management issues in weather modification has been
aphoristically summed up in the following statement by C rutch e c .
Weather modification is in the throes of a serious schizoid process. The slow
and sober business of piecing together the scientific knowledge of weather proc-
esses, developing the capacity to model the complex systems involved, and assess-
ing svstematieallv the results of modification efforts has led to responsible opti-
mism about the future of these new technologies. Ou the other hand, the social
technology” of evaluation, choice, and execution has lagged badly. The present de-
cisionmaking apparatus appears woefully inadequate to the extraordinarily diffi-
cult task of fitting weather modification into man's pattern of life in optimal
fashion There are too many game plans, too many coaches, and a disconcerting
proclivity for running hard before deciding which goal line to aim for— or, indeed,
which field to play on. ^ .
Mounting evidence indicates that weather modification of several types is,
or may soon become technically feasible. That some groups will derive economic
or other social benefits from such technology is a spur to action. But a whole
thunderhead of critical questions looms on the horizon waiting to be resolved
before any valid decisions can be made about the scale, composition, location,
and management of possible operations. 9
ADVANTAGES
In a study for the Interdepartmental Committee for Atmospheric
Sciences, Homer E. Newell highlighted the potential benefits of inten-
tional weather modification :
The Earth’s weather has a profound influence on agriculture, forestry, water
resources, industry, commerce, transportation, construction, field operations,
commercial fishing" and many other human activities. Adverse effects of weather
on man’s activities and the Earth’s resources are extremely costly, amounting
to billions of dollars per year, sometimes causing irreparable damage as when
human lives are lost in severe storms. There is, therefore, great motivation
to develop effective countermeasures against the destructive effects of weather,
and, conversely, to enhance the beneficial aspects. The financial and other ben-
efits to human welfare of being able to modify weather to augment water
supplies, reduce lightning, suppress hail, mitigate tornadoes, and inhibit the full
development of hurricanes would be very great. 10
More recently, Louis J. Battan gave the following two reasons, with
graphic examples, for wanting to change the weather :
First, violent weather kills a great many people and does enormous property
damage. A single hurricane that struck East Pakistan in November 1970 killed
more than 250,000 people in a single day. Hurricane Camille hit the United States
in 1969 and did approximately $1.5 billion worth of damage. An outbreak of
tornadoes in the Chicago area on Palm Sunday of 1965 killed about 250 people,
and the tornadoes of April 1974 did likewise. Storms kill people and damage
property, and it is reasonable to ask whether it is necessary for us to accept
this type of geophysical destruction. I say, “No, it is not — it should be possible
to do something.”
Second, weather modification involves, and in some respects might control,
the production of those elements we need to survive. Water and food are cur-
rently in short supply in many areas, and these shortages almost certainly will
be more severe in the future. We can develop new strains of wheat and rye and
com and soybeans and rice, but all is for naught if the weather fails to coop-
erate. If the monsoons do not deliver on schedule in India, residents of that
country starve in large numbers. And if the drought that people have been
predicting for the last several years does spread over the Great Plains, there
will be starvation around the world on a scale never before experienced.
Weather is the one uncontrollable factor in the whole business of agriculture.
Hail, strong winds, and floods are the scourges of agriculture, and we should
not have to continue to remain helpless in the face of them. It may be impossible
9 Crutchfield. .Tames A.. “Social Choice and Weather Modification : Concepts and Measure-
ment of Impact.’’ In W. R. Derrick Sewell (editor). Modifying the Weather: a Social
Assessment, Victoria, British Columbia, University of Victoria. 197H, p. 187.
10 Newell, Homer E., “A Recommended National Program in Weather Modification.” Fed-
eral Council for Science and Technology, Interdepartmental Committee for Atmospheric
Sciences, ICAS report No. 10a, Washington, D.C., November 1966, p. 1.
4
for us to develop the kind of technology we would like to have for modification
of weather, but to assume failure in such an important endeavor is a course
not to be followed by wise men . 11
Specific statistics on annual losses of life and economic losses from
property damages resulting from weather-related disasters in the
United States are shown in table 1, which was developed in a recent
study by the Domestic Council. 12 In the table, for comparison, are
the fiscal year 1975 expenditures by the Federal Government in
weather modification research, according to the several categories of
weather phenomena to be modified. Although it is clear that weather
disasters can be mitigated only partially through weather modifica-
tion, even if the technology were fully developed, the potential value,
economic and otherwise, should be obvious. The following quotation
from a Federal report written over a decade ago summarizes the full
potential of benefits to mankind which might be realized through use
of this technology :
With advances in his civilization, man has learned how to increase the fruit
of the natural environment to insure a livelihood. * * * it is fortunate that
growing knowledge of the natural world has given him an increasing awareness
of the changes that are occurring in his environment and akso hopefully some
means for deliberate modification of these trends. An appraisal of the prospects
for deliberate weather and climate modification can be directed toward the
ultimate goal of bringing use of the environment into closer harmony with its
capacities and with the purposes of man — whether this be for food production,
relief from floods, assuring the continuance of biologic species, stopping pollu-
tion, or for purely esthetic reasons . 13
TABLE 1.— ANNUAL PROPERTY DAMAGE AND LOSS OF LIFE FROM WEATHER-RELATED DISASTERS AND HAZARDS
IN THE UNITED STATES AND FISCAL YEAR 1975 FEDERAL WEATHER MODIFICATION RESEARCH FUNDING (FROM
DOMESTIC COUNCIL REPORT, 1975)
Property Modification
damage* research
Weather hazard Loss of life 1 (billions) (millions)
Hurricanes 2 30 2 $0.8 2 $o. 8
Tornadoes 2 140 2 .4 * 1.0
Hail s.8 3.9
Lightning 6 110 .1 .4
Fog U,000 7.5 1.3
Floods 8 240 8 2.3
Frost (agriculture) ? 1A
Drought 7.7 93.4
Total 1,520 6.7 10.8
1 Sources: "Assessment of Research on Natural Hazards," Gilbert F. White and J. Eugene Haas, the MIT Press, Cam-
bridge, Mass., 1975, pp 68 , 286, 305, 374; “The Federal Plan for Meteorological Services and Supporting Research, Fiscal
Year 1976," U.S. Department of Commerce, National Oceanic and Atmospheric Administration (NOAA), Washington, D.C.,
April 1975, p 9; "Weatherwise," February 1971, 1972, 1973, 1974, 1975, American Meteorological Society, Boston, Mass.;
“Summary Report on Weather Modification, Fiscal Years 1969, 1970, 1971," U.S. Department of Commerce, NOAA, Wash-
ington, D.C., May 1973, pp 72, 81; "Estimating Crop Losses Due to Hail— Working Data for County Estimates," U.S. De-
partment of Agriculture, Economic Research Service, September 1974; "Natural Disasters: Some Empirical and Economic
Considerations/' G. Thomas Sav, National Bureau of Standards, Washington, D.C., February 1974, p 19; Traffic Safety
magazine, National Safety Council, February 1974.
2 1970-74 average.
2 These funds do not include capital investment in research aircraft and instrumentation primarily for hurricane modi-
fication, which in fiscal year 1975 amounted to $9,200,000.
Hhese funds support theoretical research on modification of extratropical cloud systems and their attendant severe
storms such as thunderstorms and tornadoes.
s 1973.
« 1950-72 average.
7 Average.
8 1965-69 average.
« These funds support precipitation augmentation research, much of which may not have direct application to drought
alleviation. ,
11 Battan, Louis .T., “The Scientific Uncertainties: a Scientist Responds.” In William A.
Thomas (editor), “Legal and Scientific Uncertainties of Weather Modification," proceed-
ings of a symposium convened at Duke University. Mur. 11-12, 11)76, by t’ e National Con-
ference of Lawyers and Scientists, Durham, N.C., Duke University Press, 11)77, p. 26.
12 U.S. Domestic Council. Environmental Resources Committee, Subcommittee on Climate
Change. “The Federal Role in Weather Modification,” December 11)75, p. 2.
13 Special Commission on Weather Modification. “Weather and Climate Modification,
National Science Foundation. NSF 6G~3, Washington, D.C., Dec. 20, 1965, p. 7.
5
TIMELINESS
The modern period in weather modification is about three decades
old, dating from events in 1946, when Schaefer and Langmuir demon-
strated that a cloud of supercooled water droplets could be transformed
into ice crystals when seeded with dry ice. Activities and interests
among scientists, the commercial cloud seeders, and Government spon-
sors and policymakers have exhibited a nearly 10-year cyclic behavior
over the ensuing years. Each of the three decades since the late 1940’s
lias seen an initial burst of enthusiasm and activity in weather modi-
fication experiments and/or operations; a midcourse period of con-
troversy, reservations, and retrenchment ; and a final period of
capability assessment and policy examination, with the issuance of
major Federal reports with comprehensive recommendations on a
future course.
The first such period ended with the publication of the final report
of the Advisory Committee on Weather Control in 1957. 14 In 1959,
Dr. Robert Brode, then Associate Director of the National Science
Foundation, summarized the significance of that study in a 1959
congressional hearing :
For 4 years the Advisory Committee studied and evaluated public and private
cloud-seeding experiments and encouraged programs aimed at developing both
physical and statistical evaluation methods. The final report of the com-
mittee * * * for the first time placed before the American public a body of
available facts and a variety of views on the status of the science of cloud
physics and the techniques and practices of cloud seeding and weather modifica-
tion. 15
The year 1966 was replete with Government weather modification
studies, major ones conducted by the National Academy of Sciences,
the Special Commission on Weather Modification of the National
Science Foundation, the Interdepartmental Committee for Atmos-
pheric Sciences, and the Legislative Reference Service of the Library
of Congress. During that year, or thereabouts, planning reports were
also produced by most of the Federal agencies with major weather
modification programs. The significance of that year of reevaluation
and the timeliness for congressional policy action were expressed by
Hartman in his report to the Congress :
It is especially important that a comprehensive review of weather modification
be undertaken by the Congress at this time, for a combination of circumstances
prevails that may not be duplicated for many years. For the first time since
1957 there now exists, in two reports prepared concurrently by the National
Academy of Sciences and a Special Commission on Weather Modification, created
by the National Science Foundation, a definitive appraisal of the entire scope
of this subject, the broad sweep of unsolved problems that are included, and
critical areas of public policy that require attention. There are currently before
the Congress several bills which address, for the first time since enactment of
Public Law 85-510. the question of the formal assignment of Federal authority
to undertake weather modification programs. And there is increasing demand
throughout the country for the benefits that weather modification may bring.
14 Establishment of the Advisory Committee on Weather Control by the Congress and its
acti T "*t 4 es are discussed in following chapters on the history of weather modification and
on Federal activities, chs. 2 and 5, respectively. Recommendations of the final report are
summarized in ch. 6. Other renorts mentioned in the following paragraphs in this section
are also discussed and referenced in chs. 5 and 6. . , . , , .
15 U.S Congress. House of Representatives, Committee on Science and Astronautics.
“Weather Modification.” Hearing. 86th Cong., 1st sess., Feb. 16, 1959, Washington, D.C
U.S. Government Printing Office 1959. p. 3. ~
18 Hartman, Lawton M. “Weather Modification and Control.” Library of Comrress
Legislative Reference Service. Apr. 27. 1966. Issued as a committee print by the Senate
Committee on Commerce. 89th Consr., 2d sess., Senate Rept. No. 1139, Washington, D.C.,
U.S. Government Printing Office, 1966, p. 1.
6
Toward the close of the third decade, a number of policy studies and
reports appeared, starting in 1973 with a second major study by the
National Academy of Sciences, and including others by the U.S. Gen-
eral Accounting Office and by the U.S. Domestic Council. The major
study of this period was commissioned by the Congress when it enacted
Public Law 94-490, the National Weather Modification Policy Act of
1976, in October of 1976. By that law the Secretary of Commerce was
directed to conduct a study and to recommend the Federal policy and a
Federal research program in weather modification. That study was
conducted on behalf of the Secretary of Commerce b} T a Weather Modi-
fication Advisory Board, appointed by the Secretary, and the required
report will be transmitted to the Congress during 1978. The importance
of that act and its mandated study was assessed by Dr. Robert M.
White, former Administrator of the National Oceanic and Atmos-
pheric Administration (NOAA), the Commerce Department agency
with administrative responsibilities and research programs in weather
modification :
The National Weather Modification Policy Act of 1076 * * * will influence
NOAA to some degree during the next year, and its effect may have a large impact
on the agency and the Nation in future years. The comprehensive study of and
report on weather modification that will result from our implementation of this
act will provide guidance and recommendations to the President and the Congress
in the areas of policy, research, and utilization of this technology. We look to this
study and report as an opportunity to help set the future course of a controversial
science and technology with enormous potential for benefit to the Nation. 17
Thus, conditions once more are ripe and the stage has been set, as in
1957 and again in 1966, for the Congress to act in establishing a defini-
tive Federal weather modification policy, one appropriate at least for
the next decade and perhaps even longer. Among other considerations,
such a policy would define the total role of the Federal Government,
including its management structure, its responsibilities for research
and development and for support operations, its authorities for regu-
lation and licensing, its obligation to develop international cooperation
in research and peaceful applications, and its function in the general
promotion of purposeful weather modification as an economically vi-
able and socially accepted technology. On the other hand, other factors,
such as constraints arising from public concern over spending, may
inhibit the development of such policy.
While some would argue that there exists no Federal policy, at least
one White House official, in response to a letter to the President, made
a statement of weather modification policy in 1975:
A considerable amount of careful thought and study lias been devoted to the
subject of weather modification and what the Federal role and. in particular, the
role of various agencies should be in this area. As a result of this study, we have
developed a general strategy for addressing weather modification efforts which
we believe provides for an appropriate level of coordination.
We believe that the agency which is charged with the responsibility for dealing
with a particular national problem should be given the latitude to seek the best
approach or solution to the problem. In some instances this may involve a form
of weather modification, while in other instances other approaches may be more
appropriate.
While we would certainly agree that some level of coordination of weather
modification research efforts is logical, we do not believe that a program under
17 F.S. Congress. House of Representatives, Committee on Science and Technology. Sub-
committee on tin* Environment and the Atmosphere. “Itriefing on the National Oceanic and
Atmospheric Administration. ” Hearings. 05th Cong., 1st sess., May 17, IS, 1977. Washing-
ton. l T .S. Government Printing Office, 1977, p. 4-5.
7
the direction of any one single agency's leadership is either necessary or desirable.
We have found from our study that the types of scientific research conducted by
agencies are substantially different in approach, techniques, and type of equip-
ment employed, depending on the particular weather phenomena being addressed.
Each type of weather modification requires a different form of program manage-
ment and there are few common threads which run along all programs . 18
Presumably, there will be a resurgence of congressional interest in
weather modification policy during the first session of the 96th Con-
gress, when the aforementioned report from the Secretary of
Commerce has been reviewed and considered. In view of the recom-
mendations in numerous recent studies and the opinions of the Weather
Modification Advisory Board (the group of experts preparing the re-
port for the Secretary of Commerce) , it seems unlikely that any action
bv the Congress would perpetuate the policy expounded in the White
House letter quoted above.
It is expected that this present report, intended as an overall review
of the subject of weather modification, will be valuable and timely dur-
ing the anticipated congressional deliberations.
DEFINITION S AND SCOPE OF REPORT
In the broadest sense, weather modification refers to changes in
weather phenomena brought on purposefully or accidentally through
human activity. Weather effects stimulated unintentionally — such as
urban influences on rainfall or fogs produced by industrial com-
plexes — constitute what is usually termed inadvertent weather modifi-
cation. On the other hand, alterations to the weather which are
induced consciously or intentionally are called planned or advertent
weather modification. Such activities are intended to influence single
weather events and to occur over relatively short time spans, ranging
from a few hours in the case of clearing airport fog or seeding a
thunderstorm to perhaps a few days when attempts are made to re-
duce the severity of hurricane winds. Weather modification experi-
ments or operations can be initiated or stopped rather promptly, and
changes resulting from such activities are transient and generally
reversible within a matter of hours.
Climate modification, by contrast, encompasses changes of long-time
climatic variables, usually affecting larger areas and with some degree
of permanence, at least in the short term. Climatic changes are also
brought about by human intervention, and they might result from
either unintentional or planned activities. There are numerous ex-
amples of possible inadvertent climate modification; however, at-
tempts to alter climate purposefully are only speculative. The con-
cepts of inadvertent weather and climate modification are defined
more extensively and discussed fully in chapter 4 of this report.
The primary emphasis of this report is on intentional or planned
modification of weather events in the short term for the general bene-
fit of people, usually in a restricted locality and for a specific time.
Such benefit may accrue through increased agricultural productiv-
18 Ross, Norman E.. Jr., letter of June 5, 1975, to Congressman Gilbert Gude. This letter
was the official White House response to a letter of April 25. 1975. from Congressmen
Gude and Donald M. Fraser and Senator Claiborne Pell, addressed to the President, urging
that a coordinated Federal program be initiated in the peaceful uses of weather modifica-
tion. The letter to the President, the reply from Mr. Ross, and comments by Congressman
Gude appeared in the Congressional Record for June 17, 1975, pp. 19201-19203. (This
statement from the Congressional Record appears in app. A.)
8
ity or other advantages accompanying augmentation of precipitation
or they may result from mitigation of effects of severe weather with
attendant decreases in losses of life or property. There are broader
implications as well, such as the general improvement of weather for
the betterment of man’s physical environment for aesthetic and cul-
tural reasons as well as economic ones. The following recent definition
sums up succinctly all of these purposes :
Weather modification is the deliberate and mindful effort by men and women
to enhance the atmospheric environment, to aim the weather at human purposes . 10
The specific kinds of planned weather modification usually consid-
ered, and those which are discussed, in turn, in some detail in chapter
3, are the folloAving:
Precipitation enhancement.
Hail suppression.
Fog dissipation.
* Lightning suppression.
Mitigation of effects of severe storms.
Planned weather modification is usually considered in the context
of its net benefits to society at large. Nevertheless, it should be recog-
nized that, in particular instances, benefits to some segment of the
population may be accompanied by unintended injuries and costs,
which may be real or perceived, to other segments. There is yet an-
other aspect of advertent weather modification, which has engendered
much controversy, both in the United States and internationally, not
designed for the benefit of those directly affected — the use of weather
modification for hostile purposes such as a weapon of Avar. This aspect
is not a major consideration in this report, although there is some
discussion in chapters 5 and 10 of congressional concern about such use
of the technology, and in chapter 10 there is also a re Anew of recent
efforts by the United Nations to develop a treaty barring hostile use
of Aveather modification. 20
FolloAving this introductory chapter, with its summary of issues,
the second chapter sets the historical perspective for Aveather modi-
fication, concentrating primarily on activities in the United States to
about the year 1070. The third chapter attempts to review the scien-
tific background, the status of technology, and selected technical prob-
lems areas in planned weather modification; Avhile chapter 4 contains
a discussion of Aveather and climate changes induced inadvertent]} 7 by
man's activities or by natural phenomena.
The Aveather modification activities of the Federal Government —
those of the Congress and the administrative and program activities
of the executrte branch agencies — are encompassed in chapter 5; and
the findings and recommendations of major policy studies, conducted
by or on liehalf of the Federal Government, are summarized in chap-
ter (>. The seventh, eighth, and ninth chapters are concerned Avith
Aveather modification activities at the level of State and local govern-
ments, bv private organizations, and in foreign countries, respectively.
1(i Weather Modification Advisory Board, “A U.S. Policy to Enhance the Atmospheric
Environment,” Oct. 21, 1977. A discussion paper, included with testimony of Harlan Cleve-
land, Chairman of the Advisory Board, in a congressional hearing: U.S. Congress. House
of Representatives, Committee on Science and Technology. Subcommittee on the Environ-
ment and tlx* Atmosphere, Weather Modification, 95th Cong., 1st sess., Oct. 2(>, 1977,
AA T nshington, D.C., U.S. Government Printing Office, 1977, p. 25.
20 Copies of the current official position of the U.S. Department of Defense on weather
modification and of the draft U.N. convention prohibiting hostile use of environmental
modification, respectively, are found in apps. B and C.
9
The increasingly important international problems related to weath-
er modification are addressed in chapter 10, while both domestic and
international legal aspects are discussed in chapter 11. Chapters 12
and 13, respectively, contain discussions on economic and ecological
aspects of this emerging technology.
The 20 appendixes to the report provide materials that are both sup-
plementary to textual discussions in the 13 chapters and intended
to be valuable sources of reference data. In particular, attention is
called to appendix D, which contains excerpts dealing with weather
modification from the statutes of the 29 States in which such activities
are in some way addressed by State law, and to appendix E, which
provides the names and affiliations of individuals within the 50 States
who are cognizant of weather modification activities and interests with-
in the respective States. The reader is referred to the table of contents
for the subjects of the remaining appendixes.
Summary or Issues in Planned Weather Modification
“The issues we now face in weather modification have roots in the
science and technology of the subject, but no less importantly in the
politics of Government agencies and congressional committees and in
public attitudes which grow out of a variety of historical, economic,
and sociological factors.” 21 In this section there will be an identifica-
tion of critical issues which have limited development of weather
modification and which influence the ability to direct weather modifi-
cation in a socially responsible manner. The categories of issues do
not necessarily correspond with the subjects of succeeding chapters
dealing with various aspects of weather modification ; rather, they are
organized to focus on those specific areas of the subject where there
has been and there are likely to be problems and controversies which
impede the development and application of this technology.
The following sections examine technological, governmental, legal,
economic, social, international, and ecological issues. Since the primary
concern of this report is with the intentional, planned use of weather
modification for beneficial purposes, the issues summarized are those
involved with the development and use of this advertent technology.
Issues and recommendations for further research in the area of inad-
vertent weather modification are included in chapter 4, in which that
general subject is fully discussed.
TECHNOLOGICAL PROBLEMS AND ISSUES
In a recent discussion paper, the Weather Modification Advisory
Board summarized the state of weather modification by concluding
that “no one knows how to modify the weather very well, or on a very
large scale, or in many atmospheric conditions at all. The first require-
ment of a national policy is to learn more about the atmosphere it-
self.” 22 Representative of the state of weather modification science
21 Fleagle, Crutchfield, Johnson, and Abdo, “Weather Modification in the Public Inter-
est,” 1973, p. 15. ^ , ,
22 Weather Modification Advisory Board. “A U.S. Policy To Enhance the Atmospheric
Environment.” Oct. 21, 1977. This discussion paper was included with the testimony ot
Mr. Harlan Cleveland, Chairman of the Advisory Board, in a recent congressional hearing :
U.S. Congress, House of Representatives, Committee on Science and Technology, Subcom-
mittee on the Environment and the Atmosphere. “Weather Modification.” 95th Cong., 1st
sess. Oct. 26, 1977, Washington, D.C., U.S. Govt. Print. Off., 1977, p. 2o.
10
and technology is the following commentary on the state of under-
standing in the case of precipitation enhancement, or rainmaking as it
is popularly called :
Today, despite the fact that modern techniques aimed at artificial stimulation
of rain rest upon sound physical principles, progress is still fairly slow. The
application of these principles is complicated by the overwhelming complexity
of atmosheric phenomena. It is the same dilemna that meteorologists face when
they attempt to predict weather. In both cases, predicting the evolution of
atmospheric processes is limited by insufficient knowledge of the effects produced
by the fairly well-known interactive mechanisms governing atmospheric phenom-
ena. Moreover, the temporal and spatial variability of atmospheric phenomena
presents an additional difficulty. Since any effects that are produced by artificial
intervention are always imposed upon already active natural processes, assess-
ment of the consequences becomes even more difficult . 23
Grant recognizes the current progress and the magnitude of remain-
ing problems when he says that :
Important^and steady advances have been made in developing technology
for applied weather modification, but complexity of the problems and lack of
adequate research resources and commitment retard progress. Advances have
been made in training the needed specialists, in describing the natural and
treated cloud systems, and in developing methodology and tools for the necessary
research. Nevertheless, further efforts are required . 24
Though it can be argued that progress in the development of weather
modification has been retarded by lack of commitment, ineffective
planning, and inadequate funding, there are specific scientific and tech-
nical problems and issues needing resolution which can be identified
beyond these management problems and the basic scientific problem
quoted above with respect to working with the atmosphere. Particular
technical problems and issues at various levels which continue to affect
both research and operational activities are listed below :
1. There is substantial diversity of opinion, even among informed
scientists, on the present state of technology for specific types of
weather modification and their readiness for application and with
regard to weather modification in general. 25
There are many who view weather modification only as a drought -
relief measure, expecting water deficits to be quickly replenished
through its emergency use; however, during such periods weather
modification is limited by less frequent opportunities; it should, in-
stead, be developed and promoted for its year-round use along with
other water management tools. 20
3. The design and analysis of weather modification experiments is
intimately related to the meteorological prediction problem, which
needs further research, since the evaluation of any attempt to modify
the atmosphere depends on a comparison between some weather pa-
rameter and an estimate of what would have happened naturally.
4. Many of the problems which restrict understanding and predic-
tion of weather modification phenomena stem from imprecise knowl-
edge of fundamental cloud processes; the level of research in funda-
23 Dennis, Arnett S., and A. Gogin. “Recommendations for Future Research In Weather
Modification,” U.S. Department of Commerce, National Oceanic and Atmospheric .Admin-
istration, environmental Research Laboratories. Boulder, Colo.. November 1077, p. 1”.
-’Grant. “Scientific and Other Uncertainties of Weather Modification,” 1977, p. 17.
25 See table 2, eh. .”. r>. 59.
26 Silverman. Bernard A., “What Do We Need in Weather Modification?” In preprints
of the Sixth Conference on Planned and Inadvertent Weather Modification, Oct. 10-12,
1977, Champaign, 111., Boston, American Meteorological Society, 1977, p. 80S.
11
mental cloud physics and cloud modeling has not kept pace with
weather modification activity. 27
5. Progress in the area of weather modification evaluation meth-
odology* has been slow, owing to the complexit} 7 of verification prob-
lems and to inadequate understanding of cloud physics and dynamics.
6. Most operational weather modification projects, usually for the
sake of economy or in the anticipation of achieving results faster and
in greater abundance, fail to include a satisfactory means for project
evaluation.
7. There are difficulties inherent in the design and evaluation of any
experiment or operation which is established to test the efficacy of
any weather modification technique, and such design requires the
inclusion of proper statistical methods.
8. In view of the highly varying background of natural weather
phenomena, statistical evaluation of seeding requires a sufficiently
long experimental period; many research projects just barely fail
to achieve significance and credibility because of early termination;
thus, there is a need for longer commitment for such projects, perhaps
5 to 10 years, to insure that meaningful results can be obtained. 28
9. There is a need to develop an ability to predict possible adverse
weather effects which might accompany modification of specific
weather phenomena ; for example, the extent to which hail suppression
or diminishing hurricane winds might- also reduce beneficial precipi-
tation, or the possibility of increasing hailfall or incidence of light-
ning from efforts to stimulate rainfall from cumulus clouds. 29
10. The translation of cloud-seeding technologies demonstrated in
one area to another geographical area has been less than satisfactory;
this has been especially so in the case of convective cloud systems,
whose differences are complex and subtle and whose classification is
complicated and sometimes inconsistent.
11. There is increasing evidence that attempts to modify clouds
in a prescribed target area have also induced changes outside the
target area, resulting in the so-called downwind or extended area
effect : reasons for this phenomenon and means for reducing negative
results need investigation.
12. There is the possibility that cloud seeding in a given area and
during a given time period has led to residual or extended time effects
on weather phenomena in the target area beyond those planned from
the initial seeding.
13. The conduct of independent cloud-seeding operations in adjacent
locations or in the neighborhood of weather modification experiments
may cause contamination of the atmosphere so that experimental
results or estimates of operational success are biased.
14. There have been and continue to be conflicting claims as to
the reliability with which one can conduct cloud-seeding operations
so that the seeding agent is transported properly from the dispensing
device to the clouds or portions of the clouds one seeks to modify.
27 Hosier. C. L.. “Overt Weather Modification.” Reviews of Geophysics and Space Phys-
ics. vol. 12. No. 3, August 1974, p. 526.
28 Simpson. Joanne, “What Weather Modification Needs.” In preprints of the Sixth
Conference on Planned and Inadvertent Weather Modification. Oct. 10—13, 1977. Cham-
paign. 111., Boston. American Meteorological Society. 1977, p. 306.
29 Hosier, "Overt Weather Modification,” 1974, p. 525.
12
15. There is need to develop, improve, and evaluate new and cur-
rently used cloud-seeding materials and to improve systems for deliv-
ery of these materials into the clouds.
16. There is need to improve the capability to measure concentra-
tions of background freezing nuclei and their increase through seed-
ing; there is poor agreement between measurements made with various
ice nucleus counters, and there is uncertainty that cloud chamber
measurements are applicable to real clouds. 30
17. In order to estimate amounts of fallen precipitation in weather
modification events, a combination of weather radar and raingage
network are often used; results from such measurement systems have
often been unsatisfactory owing to the quality of the radar and its
calibration, and to uncertainties of the radar-raingage intercalibration.
18. There is continuing need for research in establishing seedability
criteria ; that is, definition of physical cloud conditions when seeding
will be effective in increasing precipitation or in bringing about some
other desired weather change.
IT Mathematical models used to describe cloud processes or account
for interaction of cloud systems and larger scale weather systems
greatly oversimplify the real atmosphere; therefore, model research
must be coupled with field research. 31
GOVERNMENTAL ISSUES
The basic problem which encompasses all governmental weather
modification issues revolves about the question of the respective roles,
if any, of the Federal, State, and local governments. Resolution of this
fundamental question puts into perspective the specific issues of where
in the several governmental levels, and to what extent, should goals be
set, policv established, research and/or operations supported, activities
regulated, and disputes settled. Part of this basic question includes
the role of the international community, considered in another section
on international issues; 32 the transnational character of weather modi-
fication may one day dictate the principal role to international orga-
nizations.
Hole of the Fed eralGo'i 'em m e n t
Because weather modification cannot be restricted by State bound-
aries and because the Federal Government has responsibilities for re-
source development and for reduction of losses from natural hazards,
few would argue that the Federal Government ought not to have some
interest and some purpose in development and possible use of weather
modification technology. The following broad and specific issues on
the role of the Federal Government in weather modification are among
those which may be considered in developing a Federal policy:
1. Should a maior policy analysis be conducted in an attempt to re-
late weather modification to the Nation’s broad goals; that is, improv-
ing human health and the quality of life, maintaining national security,
providing sufficient energy supplies, enhancing environmental duality,
and the production of food and fiber? Barbara Farhar suggests that
such a study has not been, but ought to be, undertaken. 33
3° Thld.
bi eionplo ot nl., “Weather Modification In the Public Interest.” 1973. n. 57.
ns Sen ?>. 2.°.
M Farhar. P.arbnrn C\. “The Societal IirmHcatlons of Weather Modification : a Review
of Issues Toward a National Policy.” P»neV£r”onnd paper prepared for the U.S. Department
of Commerce Weather Modification Advisory Hoard, Mar. 1, 1977, p. 2.
13
2. Should the Federal Government commit itself to planned weather
modification as one of several priority national goals? It can be argued
that such commitment is important since Federal program support and
political attitudes have an important overall influence on the develop -
ment and the eventual acceptance and application of this technology.
3. Is there a need to reexamine, define, and facilitate a well-balanced,
coordinated, and adequately funded Federal research and development
program in weather modification? Many argue that the current Fed-
eral research program is fragmented and that the level of funding is
subcritical.
4. Is there a suitable Federal role in weather modification activities
beyond that of research and development — such as project evaluation
and demonstration and operational programs? If such programs are
advisable, how can they be identified, justified, and established ?
5. Should the practice of providing Federal grants or operational
services by Federal agencies to States for weather modification in times
of emergency be reexamined, and should procedures for providing such
grants and services be formalized ? It has been suggested that such as-
sistance in the past has been haphazard and has been provided after it
was too late to be of any practical benefit.
6. Should the organizational structure of the Federal Government
for weather modification be reexamined and reorganized ? If so, what
is the optimum agency structure for conducting the Federal research
program and other functions deemed to be appropriate for the Federal
Government ?
7. What is the role of the Federal Government, if any, in regulation
of weather modification activities, including licensing, permitting,
notification, inspection, and reporting? If such a role is to be modified
or expanded, how should existing Federal laws and/or regulations be
modified ?
8. If all or any of the regulatory functions are deemed to be more ap-
propriate for the States than for the Federal Government, should the
Federal Government consider mandating minimum standards and
some uniformity among State laws and regulations?
9. Should the Federal Government attempt to develop a means ade-
quate for governing the issues of atmospheric water rights between
States, on Federal lands, and between the United States and neighbor-
ing countries ?
10. Where federally sponsored research or possible operational
weather modification projects occupy the same locale as local or
State projects, with the possibility of interproject contamination,
should a policy on project priorities be examined and established?
11. Should the Federal Government develop a policy with regard
to the military use of weather modification and the active pursuit of
international agreements for the peaceful uses of weather modifica-
tion ? This has been identified as perhaps one of the most important
areas of Federal concern. 34
12. Is there a need to examine and define the Federal responsibility
for disseminating information about the current state of weather
modication technology and about Federal policy, including the capa-
bility for providing technical assistance to the States and to others?
£4 Farhar Barbara f\. “What Does Weather Modification Need’’— In preprints of Uie
Sixth Conference on Planned and Inadvertent Weather Modification, Oct. 10—13, 1977,
Champaign, 111., Boston, American Meteorological Society, 1977, p. 299.
14
13. Should there be a continuing review of weather modification
technology capabilities so that Federal policy can be informed regard-
ing the readiness of technologies for export to foreign nations., with
provision of technical assistance where and when it seems feasible? 35
14. How does the principle of cooperative federalism apply to
weather modification research projects and possible operations carried
out within the States? Should planning of projects with field activities
in particular States be done in consultation with the States, and should
cooperation with the States through joint funding and research efforts
be encouraged ?
15. What should be the role of the single Federal agency whose
activities are most likely to be affected significantly by weather modi-
fication technology and whose organization is best able to provide
advisory services to the States — the U.S. Department of Agriculture?
Among the several agencies involved in weather modification, the
Department of Agriculture has demonstrated least official interest
and has not provided appreciable support to development of the
technology. 30
Roles of State and local governments
State and local 37 governments are in many ways closer to the
public than the Federal Government — often as a result of more direct
contact and personal acquaintance with officials and through greater
actual or perceived control by the voters. Consequently, a number of
weather modification functions, for both reasons of practical effi-
ciency and social acceptance, may be better reserved for State and/or
local implementation. Since weather phenomena and weather modifica-
tion operations cannot be restricted by State boundaries or by bound-
aries within States, however, manv functions cannot be carried out
in isolation. Moreover, because of the economy in conducting research
and development on a common basis — and perhaps performing other
functions as well — through a single governmental entity, such as an
agency or agencies of the Federal Government, it may be neither
feasible nor wise for State governments (even less for local jurisdic-
tions) to carry out all activities.
Thus, there are activities which might best be reserved for the States
(and possibly for local jurisdictions within States), and those which
more properly belong to the Federal Government. In the previous
list of issues on the role of the Federal Government, there was allusion
to a number of functions which might, wholly or in part, be the re-
sponsibility of either Federal or State governments; most of these
will not be repeated here. Issues and problems concerned primarily
with State and local government functions are listed below :
1. State weather modification laws, where they exist, are nonnni-
form in their requirements and specifications for licensing, permitting,
inspection, reporting, liabilities, and penalties for violations. More-
over, some State laws and policies favor weather modification, while
others oppose the technology.
2. Authorities for funding operational and research projects with-
in States and local jurisdictions within States, through public funds
** n*id.
3rt ( 'hangnon, “The Federal Hole in Woathpr Modification,” p. 11.
n7 “"Local” 1 ere rpfprs broadly to any jurisdiction below the State level : it could include
cities, townships, counties, groups of counties, water districts, or any other organized area
operating under public authority.
15
or through special tax assessments, vary widely and, except in a few
States, do not exist.
3. Decisionmaking procedures for public officials appear to be often
lacking; these could be established and clarified, especially as the pos-
sibility of more widespread application of weather modification tech-
nology approaches.
4. Many public officials, usually not trained in scientific and en-
gineering skills, often do not understand weather modification tech-
nology, its benefits, and its potential negative consequences. Some
training of such officials could contribute to their making wise de-
cisions on the use of the technology, even without complete informa-
tion on which to base such decisions.
5. Many weather modification decisions have had strong political
overtones, with some legislators and other public officials expressing
their views or casting their votes allegedly on the basis of political
expediency rather than on the basis of present or potential societal
benefits.
6. State and local authorities may need to provide for the education
of the general public on the rudiments of weather modification, on its
economic benefits and disbenefits, and on other societal aspects.
7. To keep communication channels open, mechanisms such as pub-
lic hearings could be established to receive comments, criticisms, and
general public sentiments on weather modification projects from in-
dividual citizens and from various interest groups.
8. Criteria and mechanisms have not been established for compen-
sating those individuals or groups within States who might be eco-
nomically injured from weather modification operations.
0. Questions of water rights within States, as well as between States,
have not been addressed and/or resolved in a uniform manner.
LEGAL ISSUES
Legal issues in weather modification are complex and unsettled.
They can be discussed in at least four broad categories :
1. Private rights in the clouds ;
2. Liability for weather modification ;
8. Interstate legal issues; and
4. International legal issues. 38
The body of law on weather modification is slight, and existing case
law offers few guidelines to determine these issues. It is often neces-
sary, therefore, to analogize weather modification issues to more set-
tled areas of law such as those pertaining to water distribution.
Private rights in the clouds
The following issues regarding private rights in the clouds may be
asked :
Are there any private rights in the clouds or in the water which
may be acquired from them?
Does a landowner have any particular rights in atmospheric
water?
Does a weather modifier haA^e rights in atmospheric water ?
38 Questions on regulation or control of weather modification activities through licensing
and permitting, while of a basic legal nature, are related to important administrative func-
tions and are dealt with under issues concerned with Federal and State activities.
16
Some State statutes reserve the ownership or right to use atmospheric
water to the State. 39
There is no general statutory determination of ownership of atmos-
pheric water and there is no well-developed body of case law. Conse-
quently, analogies to the following general common law doctrines may
be helpful, but each has its own disadvantages when applied to weather
modification :
1. The doctrine of natural rights, basically a protection of the land-
owner’s right to use his land in its natural condition (i.e., precipita-
tion is essential to use of the land as are air, sunlight, and the soil
itself).
2. The ad coelum doctrine which states that whoever owns the land
ought also to own all the space above it to an indefinite extent.
3. The doctrine of riparian rights, by which the one owning land
which abuts a watercourse may make reasonable use of the water, sub-
ject to similar rights of others whose lands abut the watercourse.
4. The doctrine of appropriation, which gives priority of right based
on actual use of the water.
5. The two main doctrines of ownership in the case of oil and gas
(considered, like water, to be “fugitive and migratory” substances) ;
that is, (a) the non-ownership theory, by which no one owns the oil and
gas until it is produced and anyone may capture them if able to do so ;
and (b) the ownership-in-place theory, by which the landowner has the
same interest in oil and gas as in solid minerals contained in his land.
6. The concept of “developed water,” that is, water that would not
be available or would be lost were it not for man’s improvements.
7. The concept of “imported water,” that is, water brought from one
watershed to another.
Liability for weather modification
Issues of liability for damage may arise when drought, flooding, or
other severe weather phenomena occur following attempts to modify
the weather. Such issues include causation as well as nuisance, strict
liability, trespass, and negligence. Other issues which could arise relate
to pollution of the air or water through introduction of artificial nu-
cleants such as silver iodide, into the environment. While statutes of
10 States discuss weather modification liability, there is much varia-
tion among the specific provisions of the laws in those States. 40
Before any case can be made for weather modification liability
based upon causation it must be proven that the adverse weather con-
ditions were indeed brought about by the weather modifier, a very
heavy burden of proof for the plaintiff. In fact, the scientific uncer-
tainties of weather modification are such that no one has ever been able
to establish causation of damage through these activities. As weather
modification technology is improved, however, the specter of a host of
liability issues is expected to emerge as evidence for causation becomes
more plausible.
While the general defense of the weather modifier against liability
charges is that causation has not been established, he may also use as
further defense the arguments based upon immunity, privilege, con-
sent , and waste.
30 Son p. 450, ch. 11, find npp, I).
40 See discussion p. 455 in ch. 11 and app. D.
17
Interstate legal issues
When weather modification activities conducted in one State affect
another State as well, significant issues may arise. The following*
problem categories are examples of some generally unresolved inter-
state issues in weather modification :
1. There may be the claim that cloud seeding in one State has removed
from the clouds water which should have fallen in a second State or
that excessive flooding in a neighboring State has resulted from seed-
ing in a State upwind.
2. Operation of cloud-seecling equipment near the border in one State
may violate local or State ordinances which restrict or prohibit weather
modification in an adjacent State, or such operations may conflict with
regulations for licensing or permitting of activities within the bor-
dering State.
Some States have attempted to resolve these issues through specific
legislation and through informal bilateral agreements. 41 Another ap-
proach would be through interstate compact, though such compacts re-
quire the consent of Congress. No compacts specifically concerned with
weather modification currently exist, though some existing compacts
allocating waters in interstate streams may be applicable to weather
modification.
International legal issues
Because atmospheric processes operate independent of national
borders, weather modification is inherently of international concern.
International legal issues have similarities to domestic interstate activi-
ties and dangers. The following serious international questions, which
have arisen in conjunction with a developing capability to modify the
weather, have been identified by Orfield : 42
Do countries have the right to take unilateral action in all
weather modification activities?
What liability might a country incur for its weather modifica-
tion operations which [might] destroy life and property in a
foreign State?
On what theory could and should that State base its claim ?
The primary international legal issue regarding weather modifica-
tion is that of liability for transnational injury or damage, which could
conceivably result from any of the following situations :
(1) injury or damage in another nation caused by weather
modification activities executed within the United States;
(2) injury or damage in another nation caused by weather
modification activities executed in that nation or a third nation by
the United States or a citizen of the United States ;
(3) injury or damage in another nation caused by weather
modification activities executed in an area not subject to the juris-
diction of any nation (e.g., over the high seas), by the United
States or a citizen thereof ; and
(4) injury or damage to an alien or an alien’s property within
the United States caused by weather modification activities exe-
cuted within the United States.
41 See discussion p. 457 in ch. 11 and app. D.
42 Orfield, Michael B., “Weather Genesis and Weather Neutralization; a New Approach
to Weather Modification,” California Western International Law Journal, vol. 6, no.
spring 1976, p. 414.
34^857-79-
4
18
Whereas domestic weather modification law is confused and unset-
tled, international law in this area is barely in the formative stage. In
time, ramifications of weather modification may lead to major interna-
tionl controversy. 43
ECONOMIC ISSUES
The potential for long-term economic gains through weather modi-
fication cannot be denied ; however, current economic analyses are tenu-
ous in view of present uncertainty of the technology and the complex
nature of attendant legal and economic problems. Meaningful economic
evaluation of weather modification activities is thus limited to special,
localized cases, such as the dispersal of cold fog at airports, where bene-
fit-cost ratios greater than f> to 1 have been realized through savings in
delayed or diverted traffic. Various estimated costs for increased pre-
cipitation through cloud seeding range from $1.50 to $2.50 per acre-
foot in the western United States.
Issues complicating economic analyses of weather modification
Costs of most weather modification operations are usually relatively
small and are normally believed to be only a fraction of the benefits
obtained through such operations. However, if all the benefits and all
the costs are considered, benefit-cost latios may be diminished. While
direct costs and benefits from weather modification are reasonably
obvious, indirect costs and benefits are elusive and require further study
of sociological, legal, and ecological implications.
Tn analyzing benefit-cost ratios, some of the following considerations
need to be examined :
Weather modification benefits must be considered in terms of
the costs for achieving the same objectives as increased precipita-
tion, e.g., through importation of water, modified use of agricul-
tural chemicals, or introduction of improved plant strains.
Costs for weather modification operations are so low in compari-
son with other agricultural investments that farmers may gamble
in spending the 5 to 20 cents per acre for operations designed to
increase rainfall or suppress hail in order to increase yield per
acre, even though the results of the weather modification opera-
tions may be doubtful.
Atmospheric conditions associated with prolonged droughts are
not conducive to success in increasing precipitation; however,
under these conditions, it is likely that increased expenditures
may be made for operations which offer little hope of economic
return.
Increased precipitation, obtained through a weather modifica-
tion program sponsored and funded by a group of farmers, can
also benefit other farmers who have not shared in the costs; thus,
the benefit-cost ratio to those participating in the program is
higher than it need be if all share in its costs.
As weather modification technology develops and programs be-
come more sophisticated, increased costs for equipment and labor
will increase direct costs to clients: indirect costs resulting from
increased State license and permit fees and liability insurance for
operators will probably also be passed on to the customer.
4 '» See <*ii . in on international aspects and p. 4<5N, eli. 11, on international legal aspects of
tv father in od i ti cn 1 1 o n .
19
The sophistication of future programs will likely incur addi-
tional costs for design, evaluation, and program information ac-
tivities, along with supporting meteorological prediction services;
these costs will be paid from public funds or by private clients, in
either case reducing the overall benefit-cost ratios.
Ultimate costs for compensation to those incurring disbenefits
from weather modification operations will offset overall benefits
and thus reduce benefit-cost ratios.
Weather modification and conflicting interests
There are numerous cases of both real and perceived economic losses
which one or more sectors of the public may suffer while another group
is seeking economic advantage through some form of weather modi-
fication. Overall benefits from weather modification are accordingly
reduced when net gains are computed from such instances of mixed
economic advantages and disadvantages. Benefits to the parties seek-
ing economic gain through weather modification will be directly re-
duced at such time when mechanisms are established for compensating
those who have suffered losses. The following are some examples of
such conflicting situations :
Successful suppression of hail may be valuable in reducing crop
damage for orchardists while other agricultural crops may suffer
from decrease of rain concomitant with the hail decrease.
Additional rainy days may be of considerable value to farmers
during their growing season but may be detrimental to the finan-
cial success of outdoor recreational enterprises.
Increased snowpack from orographic cloud seeding may be
beneficial to agricultural and hydroelectric power interests but
increases the costs for maintaining free passage over highways
and railroads in mountainous areas.
Successful abatement of winds from severe storms, such as those
of hurricanes, may result in decreased precipitation necessary for
agriculture in nearby coastal regions or may redistribute the ad-
verse storm effects, so that one coastal area is benefitted at the ex-
pense of others.
SOCIAL ISSUES
It has been said that “weather modification is a means toward so-
cially desired ends, not an end in itself. It is one potential tool in a set
of possible societal adjustments to the vagaries of the weather. Iden-
tifying when, where, and how to use this tool, once it is scientifically
established, is the primary need in weather modification .” 44 It is likely
that, in the final analysis, the ultimate decisions on whether weather
modification should and will be used in any given instance or will be
adopted more generally as national or State programs depends on
social acceptance of this tool, no matter how well the tool itself has
been perfected. That this is increasingly the case has been suggested by
numerous examples in recent years. Recently Silverman said :
Weather modification, whether it be research or operations, will not progress
wisely, or perhaps at all, unless it is considered in a context that includes everyone
44 Farhar. Barbara C. “What Does Weather Modification Need ?’’ In preprints of the Sixth
Conference on Planned and Inadvertent Weather Modification. October 10-13, 1977, Cham-
paign, 111. Boston. American Meteorological Society, 1977. p. 296.
20
that may be affected. We must develop and provide a new image of weather
modification. 45
Regardless of net economic benefits, a program is hard to justify
when it produces obvious social losses as well as gains.
Research in the social science of weather modification has not kept
pace with the development of the technology, slow as that has been.
In time, this failure may be a serious constraint on further develop-
ment and on its ultimate application. In the past, organized opposition
has been very effective in retarding research experiments and in cur-
tailing operational cloud-seeding programs. Thus, there is need for an
expanded effort in understanding public behavior toward weather
modification and for developing educational programs and effective
decisionmaking processes to insure intelligent public involvement in
eventual application of the technology.
Social issues discussed in this section are those which relate to public
behavior and public response to weather modification, while societal
issues are generally considered to include economic, legal, and other
nontechnical issues as Veil as the social ones. These other aspects of
societal issues were discussed in preceding sections. In the subsections
to follow there are summaries of social implications of weather modifi-
cation, the need for public education, and the problem of
decisionmaking.
Social factors
It has been said that social factors are perhaps the most elusive and
difficult weather modification externalities to evaluate since such fac-
tors impinge on the vast and complex area of human values and at-
titudes . 46 FI eagle, et al., identified the following important social
implications of weather modification, which would presumably be
taken into account in formulation of policies : 47
1. The individuals and groups to be affected, positively or negatively, by the
project must be defined. An operation beneficial to one party may actually harm
another. Or an aggrieved party may hold the operation responsible * * * for
damage * * * which might occur at the same time or following the modification.
2. The impact of a contemplated weather modification effort on the general
well-being of society and the environment as a whole must be evaluated. Con-
sideration should be given to conservationists, outdoor societies, and other
citizens and groups representing various interests who presently tend to ques-
tion any policies aimed at changes in the physical environment. It is reasonable
and prudent to assume that, as weather modification operations expand, question-
ing and opposition by the public will become more vocal.
3. Consideration must be given to the general mode of human behavior in
response to innovation. There are cases where local residents, perceiving a cause
and effect relationship between economic losses from severe weather and nearby
weather modification operations, have continued to protest, and even to threaten
violence, after all operations have been suspended.
4. The uniqueness and complexity of certain weather modification operations
must be acknowledged, and special attention should be given to their social and
legal implications. The cases of hurricanes and tornadoes are especially perti-
nent. Alteration of a few degrees in the path of a hurricane may result in its
missing a certain area * * * and ravaging * * * instead, a different one. The decision
on whether such an operation is justified can reasonably be made only at the
highest level, and would need to be based on the substantial scientific finding
that the anticipated damages would be less than those originally predicted had
the hurricane been allowed to follow its course.
i: ‘ Silverman, Pornard A. “What Do Wo Nood in Woathor Modification?” In preprints of
t)io Sixth Conference on Planned and Inadvertent Weather Modification, October 10-13,
1077. Champaign, 111., Poston. American Meteorological Society. 1077. p. 310.
Fle igle. Crutchfield, Johnson, and Abdo. “Weather Modification in the Fublic Interest.”
1074. p. 37-38.
47 Ibid., p. 38-40.
21
5. Attention must be given to alternatives in considering a given weather
modification proposal. The public may prefer some other solution to an attempt
at weather tampering which may be regarded as predictable and risky. Further-
more, alternative policies may tend to be comfortable extensions of existing
policies, or improvements on them, thus avoiding the public suspicion of inno-
vation. In an area such as weather modification, where so many uncertainties
exist, and where the determination or assigning of liability and responsibility
are far from having been perfected, public opposition will surely be aroused.
Any alternative plan or combination of plans will have its own social effects,
however, and it is the overall impact of an alternative plan and the adverse
effects of not carrying out such a plan which, in the final analysis, should guide
decisions on alternative action.
6. Finally, it is important to recognize that the benefits from a weather modi-
fication program may depend upon the ability and readiness of individuals
to change their modes of activity. The history of agricultural extension work
in the United States suggests that this can be done successfully, but only with
some time lag, and at a substantial cost. Social research studies suggest that
public perception of flood, earthquake, and storm hazards is astonishingly casual.
Need for public education on weather modification
The previous listing* of social implications of weather modification
was significantly replete with issues derived from basic human atti-
tudes. To a large extent these attitudes have their origin in lack of in-
formation, misconceptions, and even concerted efforts to misinform by
organized groups which are antagonistic to weather modification. As
capabilities to modify weather expand and applications are more wide-
spread, it would seem probable that this information gap would also
widen if there are no explicit attempts to remedy the situation. “At the
very least,’’ according to Fleagle, et al., “a large-scale continuing pro-
gram of education (and perhaps some compulsion) will be required if
the potential social gains from weather modification are to be realized
in fact.” 48 Whether such educational programs are mounted by the
States or by some agency of the Federal Government is an issue of
jurisdiction and would likely depend on whether the Federal Govern-
ment or the States has eventual responsibility for management of op-
erational weather modification programs. Information might also be
provided privately by consumer groups, professional organizations,
the weather modification industry, or the media.
It is likely that educational programs would be most effective if a
variety of practical approaches are employed, including use of the
news media, publication of pamphlets at a semitechnical level, semi-
nars and hearings, and even formal classes. Probably the latter cate-
gories would be most appropriate for civic groups. Government offi-
cials, businessmen, or other interests who are likely to be directly
affected by contemplated operations.
The following list of situations are examples of public lack of under-
standing which could, at least in part, be remedied through proper
educational approaches :
There is much apprehension over claims of potential danger of a
long-lasting nature on climate, which could supposedly result
from both inadvertent and planned modification of the weather,
with little insight to distinguish between the causes and the scales
of the effects.
There have been extravagant claims, propagated through ig-
norance or by deliberate distortion by antagonistic groups, about
48 Ibid., p. 40.
22
the damaging effects of cloud seeding on ecological systems, human
health, and air and water quality.
The controversies between opposing groups of scientists on the
efficac}^ of weather modification technologies and between scien-
tists and commercial operators on the readiness of these technolo-
gies for application has engendered a mood of skepticism and
even mistrust of weather modification on the part of a public
which is largely uninformed on technical matters.
The public has often been misinformed by popular news media,
whose reporters seek to exploit the spectacular in popular weather
modification “stories” and who, themselves usually uninformed in
technical aspects of the subject, tend to oversimplify and distort
the facts associated with a rather complex science and technology.
There has been an organized effort on the part of groups opposed
to weather modification to mount an educational program which
runs counter to the objectives of informing the public about the
potential benefits of. a socially acceptable technology of weather
modification.
Portions of the public have acquired a negative impression that
meteorologists and Government officials concerned with weather
modification are irresponsible as a result of past use. or perceived
present and future use. of the technology as a weapon of war.
Lack of information to the public has sometimes resulted in
citizen anger when it is discovered that a seeding project has been
going on in their area for some time without their having been
informed of it.
Decisionm (iking
“The nature of weather processes and the current knowledge about
them require that most human decisions as to weather modification
must be made in the face of uncertainty. This imposes special re-
straints on public agencies and it increases the difficulty of predict-
ing how individual farmers, manufacturers, and others who are
directly affected bv weather would respond to changes in weather
characteristics.” 40 The situation since 1005 when this statement was
made has changed little with regard to predictability of weather
processes and their modification. There has also been little progress
toward developing decisionmaking processes which can be applied,
should the need arise, on whether or not weather modification should
be employed.
A number of studies on social attitudes indicate that the preference
of most citizens is that decisionmaking in such areas as use or restraint
from use of weather modification should be at the local level, owing
to the feeling that citizens’ rights and property are best protected
when decisions are made bv officials over whom they have the most
direct control. Fnrhar savs that evidence suggests that one important
condition for public acceptance of weather modification technology
is public involvement in the decision process, especially in civic
decisions . 50 Procedures must then be developed for enabling local
4ft Special Commission on Weather Modification. “Weather and Climate Modification.”
NSC Ofi 3. 1005. n. 90.
w> Fnrhar. Barbara C. "The Public Per-ides About Weather Modification.” Environment
and Behavior, vol. 0. No. 3, September 1077, p. 307.
23
officials, probably not technically trained, to make such decisions
intelligently. Such decisions must be based both on information
received from Federal or State technical advisers and on the opinions
of local citizens and interest groups.
INTERNATIONAL ISSUES
International agreements regarding weather modification experi-
ments and operations have been very limited. There exists a United
States-Canada agreement, which requires consultation and notifica-
tion of the other country when there is the possibility that weather
modification activities of one country could affect areas across the
border. 51 Earlier understandings were reached between the United
States and Canada concerning experiments over the Great Lakes and
with the United Kingdom in connection with hurricane modification
research in the Atlantic. 52 Recent attempts to reach agreement with
the Governments of Japan and the People's Republic of China for
U.S. experiments in the Far East on modification of typhoons were
unsuccessful, though such research was encouraged by the Philip-
pines. There is current intention to reach an agreement with Mexico
on hurricane research in the eastern Pacific off that nation’s coast.
During 1976, 25 nations reported to the World Meteorological Orga-
nization that they had conducted weather modification activities. 53
There have been two principal international activities, dealing with
somewhat different aspects of weather modification, in recent years.
One of these is the preparation and design of a cooperative experi-
ment under the auspices of the World Meteorological Organization,
called the Precipitation Enhancement Experiment (PEP) ; while the
other is the development of a convention by the United Nations on
the prohibition.of hostile use of environmental modification. 54
The following international considerations on research and opera-
tional weather modification activities can be identified :
1. There is a common perception of a need to insure that the current
high level of cooperation which exists in the international community
with regard to more general meteorological research and weather re-
porting will be extended to development and peaceful uses of planned
weather modification.
2. There is now no body of international law which can be applied to
the potentially serious international questions of weather modification,
such as liability or ownership of atmospheric Avater resources. 55
3. Past use by the United States, and speculated current or future
use by various countries, of weather modification as a weapon have
raised suspicions as to the possible intent in developing advertent
weather modification technology.
4. There have been charges that weather modification research activi-
ties were used to divert severe weather conditions away from the
51 The United States-Canada agreement on weather modification is reproduced in app. F.
52 Taubenfeld, Howard J., “National Weather Modification Policy Act of 1976; Interna-
tional Agreements.” Background paper for use of the U.S. Department of Commerce
Weather Modification Advisory Board, March 1977, p. 13.
53 See table 1, ch. 9, p. 409.
64 These activities and other international aspects of weather modification are discussed
in ch. 10.
55 See previous section on legal issues, p. 17.
24
United States at the expense of other countries or that such activities
have resulted in damage to the environment in those countries. 56
5. As in domestic research projects, there are allegations of insuffi-
cient funding over periods of time too short to achieve significant
results in the case of internationally sponsored experiments; in par-
ticular, many scientists feel that a means should be devised to insure
that the planned Precipitation Enhancement Project (PEP) receives
adequate continuous support.
6. Other nations should be consulted with regard to any planned
weather modification activities by the United States which might con-
ceivably affect, or be perceived to affect, those countries.
ECOLOGICAL ISSUES
The body of research on ecological effects of weather modification
is limited but significantly greater than it was a decade ago. It is
still true that much remains unknown about ecological effects of
changes to weather and climate.
Economically significant weather modification will always have an
eventual ecological effect, although appearance of that effect may be
hidden or delayed by system resilience and/or confused by system
complexity. It may never be possible to predict well the ecological
effects of weather modification; however, the more precisely the
weather modifier can specify the effects his activities will produce in
terms of average percentage change in precipitation (or other vari-
ables), expected seasonal distribution of the induced change, expected
year-to-year distribution of the change, and changes in relative form
of precipitation, the more precise can be the ecologist’s prediction of
possiblo ecological effects.
Ecological effects will result from moderate weather- related shifts
in rates of reproduction, growth, and mortality of plants and animals;
they will rarely be sudden or catastrophic. Accordingly, weather modi-
fications which occur with regularly over time are the ones to which
biological communities will react. Adjustments of plant and animal
communities will usually occur more slowly in regions of highly vari-
able weather than in those with more uniform conditions. Deliberate
weather modification is likely to have greater ecological impact in
semi arid systems and less impact in humid ones. Since precipitation
augmentation, for example, would have the greatest potential for eco-
nomic value and is, therefore, likely to have its greatest potential ap-
plication in such areas, the ecological impacts in transition areas will
be of particular concern.
Although widespread cloud seeding could result in local, temporary
increases in concentrations of silver (from the most commonly used
seeding agent, silver iodide), approaching the natural quantities in
sni-face waters, the exchange rates would probably be an order of
magnitude lower than the natural rates. Even in localized areas of
precipitat ion management, it appears that exchange rates will be many
orders of magnitude smaller than those adversely affecting plants and
soils. Further research is required, however, especially as other poten-
tial seeding agents are introduced.
r>« For example, there wore charges that attempts to mitigate severe effects of Hurricane
Fifi in 107.1 caused devastation to Honduras, n charge whieh the United States officially
denied, since no hurricanes had been seeded under Project. Stornifury since 1071.
CHAPTER 2
HISTORY OF WEATHER MODIFICATION
(By Robert E. Morrison, Specialist in Earth Sciences, Science Policy Research
Division, Congressional Research Service)
Introduction
The history of the desire to control the weather can be traced to
antiquity. Throughout the ages man has sought to alleviate droughts or
to allay other severe weather conditions which have adversely affected
him by means of magic, supplication, pseudoscientific procedures such
as creating noises, and the more on less scientifically based techniques
of recent times.
The expansion in research and operational weather modification
projects has increased dramatically since World War II ; nevertheless,
activities predating this period are of interest and have also provided
the roots for many of the developments of the “modern” period. In a
1966 reprt for the Congress on weather modification, Lawton Hart-
man stated three reasons why a review of the history of the subject
can be valuable: (1) Weather modification is considerably older than
is commonly recognized, and failure to consider this fact can lead to a
distorted view of current problems and progress. (2) Weather modi-
fication has not developed as an isolated and independent field of re-
search, but for over a century has been parallel to and related to
progress in understanding weather processes generally. (3) Earlier
experiences in weather modification may not have been very different
from contemporary experiences in such matters as experimental de-
sign, evaluation of results, partially successful projects, and efforts to
base experiments on established scientific principles. 1
Hartman found that the history of weather modification can be
conveniently divided into five partially overlapping periods. 2 He refers
to these as (1) a prescientific period (prior to about 1839); (2) an
early scientific period (extending approximately from 1839 through
1891) ; (3) a period during which elements of the scientific framework
were established (from about 1875 to 1933) ; (4) the period of the
early cloud-seeding experiments (1921 to 1946) ; and (5) the modern
period, beginning with the work of Langmuir, Schaefer, and Vonne-
gut (since 1946). This same organization is adopted in discussions
below ; however, the four earlier periods are collected into one section,
while the more significant history of the extensive activities of the
post-1946 period are treated separately.
1 Hartman, Lawton M., “History of Weather Modification.” In U.S. Congress. Senate
Committee on Commerce “Weather Modification and Control.” Washington. D.C.. U.S.
Government Printing Office, 1966 (89th Cong., 2d sess., Senate Rept. No. 1139: prepared
by the Legislative Reference Service, the Library of Congress, at the request of Warren G.
Maernn«on), p. 11
2 Ibid.
( 25 )
26
History of Weather Modification Prior to 1946
FRESCIENTIFIC FERIOD
From ancient times through the early 19th century, and even since,
there have been reported observations which led many to believe that
rainfall could be induced from such phenomena as great noises and
extensive fires. Plutarch is reported to have stated, “It is a matter of
current observation that extraordinary rains pretty generally fall
after great battles.*’ 3 Following the invention of gunpowder, the fre-
quency of such claims and the conviction of those espousing this
hypothesis increased greatly. Many cases were cited where rain fell
shortly after large battles. A practical use of this phenomenon was re-
ported to have occurred in the memoirs of Benvenuto Cellini when, in
1539 on the occasion of a procession in Pome, lie averted an impending
rainstorm by firing artillery in the direction of the clouds, “which had
already begun to drop their moisture.” 4
William Humphreys jposed a plausible explanation for the appar-
ently high correlation between such weather events and preceding
battles. He noted that plans were usually made and battles fought in
good weather, so that after the battle in the temperate regions of
Europe or North America, rain will often occur in accordance with
the natural 3- to 5-day periodicity for such events. 5 Even in modern
times there was the conviction that local and global weather had been
adversely affected after the explosion of the first nuclear weapons and
the various subsequent tests in the Pacific and elsewhere. 6 Despite
statements of the U.S. Weather Bureau and others pointing out the
fallacious reasoning, such notions became widespread and persistent. 7
In addition to these somewhat rational though unscientific obser-
vations, many of which were accompanied by testimony of reliable
witnesses, there had been, and there still exist in some primitive cul-
tures, superstitions and magical practices that accompany weather
phenomena and attempts to induce changes to the weather. Daniel
ITalacv relates a number of such superstitiouslike procedures which
have been invoked in attempts to bring rain to crops during a drought
or to change the weather in some other way so as to be of particular
benefit to man : 8
Primitive rainmakers would often use various intuitive gestures, such as
sprinkling water on the soil that they wanted the heavens to douse, blowing
mouthfuls of water into the air like rain or mist, hammering on drums to imi-
tate thunder, or throwing firebrands into the air to simulate lightning.
Women would carry water at night to the field and pour it out to coax the
skies to do likewise.
American Indians blew water from special pipes in imitation of the rainfall.
It was believed that frogs came down in the rain because many were seen
following rain : therefore, frogs were hung from trees so that the heavens would
pour down rain upon them.
Sometimes children were buried up to tlieir necks in the parched ground and
then cried for rain, their tears providing the imitative magic.
3 Ward. R. Do C\, “Artificial Rain : a Review of t lie Subject to the Close of 1880.” Amer-
ican Meteorological Journal, vol. 8, May ISOl-April 1802, p. 4S4.
4 Ibid., p. 40”.
R Humphreys. William J., “Rain Making and Other Weather Vagaries.” Baltimore, The
Williams and Wilkins Co.. 102(5. p. 31.
f livers. Horace R., “History of Weather Modification.” In Wilnot N. Hess (editor),
“Weather and Climate Modification,” New York, Wiley, 1074. p. 4.
7 Ibid
* ITalaey. Daniel S., Jr., “The Weather Changers,” New York. Harper & Row. 1008, pp.
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